Greek Text · Translation · Interlinear · Discourse Structure

The First Epistle to the Corinthians, Chapter 8ΠΡΟΣ ΚΟΡΙΝΘΙΟΥΣ Α′ Η′

Each verse opens with the running Greek, an English translation, and a discourse note (its connective, relation, and role in the argument). Below follows the word-by-word breakdown in six tiers: gloss, case (color), parsing, syntax, semantic force, and a lexical note.

Case Nominative Genitive Dative Accusative Vocative Verb (no case) Indeclinable

Discourse notes head each verse: relation · connective · clause-flow. Indentation marks prominence — flush-left = main line of argument; indented = supporting / subordinate material.

1

Περὶ δὲ τῶν εἰδωλοθύτων, οἴδαμεν ὅτι πάντες γνῶσιν ἔχομεν. ἡ γνῶσις φυσιοῖ, ἡ δὲ ἀγάπη οἰκοδομεῖ·

Now concerning things sacrificed to idols: we know that we all have knowledge. Knowledge puffs up, but love builds up.

New topic / responseΠερὶ δὲΠερὶ δέ marks a fresh reply to the Corinthians' letter (as at 7:1, 7:25). Paul cites their slogan ('we all have knowledge') only to subordinate it instantly to a higher principle: love, not knowledge, edifies.
Περὶconcerningpreposition + genitive (reference)
δὲnowtransitional conjunction (new topic)δέ: here a discourse marker; Περὶ δέ signals Paul turning to the next item from the Corinthians' inquiry.
τῶνtheGenitivearticle
εἰδωλοθύτωνthings sacrificed to idolsGenitiveobject of Περί (topic)εἰδωλόθυτον: 'idol-sacrifice' (εἴδωλον + θύω), meat offered to a pagan deity, then sold or eaten at temple feasts; a coinage of Jewish/Christian polemic.
οἴδαμενwe knowPerf Act Indic 1 Pl · οἶδαmain verb→ intensive perfect (present sense)οἶδα: 'know' (perfect with present meaning); introduces shared common ground — possibly echoing the Corinthians' own claim.
ὅτιthatconjunction (content of οἴδαμεν)
πάντεςallNominativesubject (substantival adj.)πᾶς: 'all'; the inclusive 'we all' frames the slogan as common property — perhaps with slight irony.
γνῶσινknowledgeAccusativedirect objectγνῶσις: 'knowledge'; the prized Corinthian commodity — here the monotheistic insight of vv.4–6, valued but insufficient.
ἔχομενwe havePres Act Indic 1 Pl · ἔχωmain verb (ὅτι clause)→ stative presentἔχω: 'have, hold'; states possession of the knowledge as a settled fact.
theNominativearticle
γνῶσιςknowledgeNominativesubjectγνῶσις: now subject of a gnomic maxim — abstract 'knowledge' personified as an agent.
φυσιοῖpuffs upPres Act Indic 3 Sg · φυσιόωmain verb (gnomic)→ gnomic presentφυσιόω: 'inflate, puff up' (from φῦσα, 'bellows'); a favorite Corinthian rebuke-word (4:6,18,19; 5:2; 13:4) — knowledge swells the ego.
theNominativearticle
δὲbutadversative conjunction
ἀγάπηloveNominativesubject (contrastive)ἀγάπη: self-giving love directed to the other's good; the counter-principle that governs the whole chapter (cf. ch. 13).
οἰκοδομεῖbuilds upPres Act Indic 3 Sg · οἰκοδομέωmain verb (gnomic, antithetic)→ gnomic presentοἰκοδομέω: lit. 'build a house'; metaphor for strengthening the community — the constructive opposite of mere self-inflation.
2

εἴ τις δοκεῖ ἐγνωκέναι τι, οὔπω ἔγνω καθὼς δεῖ γνῶναι·

If anyone supposes that he knows something, he does not yet know as he ought to know;

Maxim / correctiveasyndetonA conditional aphorism puncturing the pretension behind 'we all have knowledge': true knowing is humble and incomplete (cf. 13:9,12). Asyndeton heightens the epigram.
εἴifconjunction (first-class condition)
τιςanyoneNominativesubject (indefinite pronoun)
δοκεῖsupposesPres Act Indic 3 Sg · δοκέωmain verb (protasis)→ customary presentδοκέω: 'think, suppose, seem'; here of self-assessment — the mere appearance of knowing, often mistaken.
ἐγνωκέναιto have knownPerf Act Inf · γινώσκωcomplementary infinitive (of δοκεῖ)→ intensive perfect (settled knowledge)γινώσκω: 'come to know'; the perfect connotes a possessed, completed knowledge — exactly the presumption being deflated.
τιsomethingAccusativeobject of ἐγνωκέναι
οὔπωnot yetnegative adverb (time)οὔπω: 'not yet'; concedes future possibility while denying present attainment.
ἔγνωhe has knownAor Act Indic 3 Sg · γινώσκωmain verb (apodosis)→ constative aoristγινώσκω: the bare aorist with οὔπω — 'he has not yet come to know'; real knowing has not occurred.
καθὼςascomparative conjunction (manner)
δεῖit is necessaryPres Act Indic 3 Sg · δεῖimpersonal verb→ stative presentδεῖ: 'it is necessary, one ought'; sets the standard of true knowing — measured by obligation, not pretension.
γνῶναιto knowAor Act Inf · γινώσκωcomplementary infinitive (of δεῖ)→ constative aoristγινώσκω: the infinitive completing δεῖ — the proper, love-shaped knowing one is bound to attain.
3

εἰ δέ τις ἀγαπᾷ τὸν θεόν, οὗτος ἔγνωσται ὑπ' αὐτοῦ.

but if anyone loves God, this one is known by him.

Antithetic correctionεἰ δέThe decisive reversal: what matters is not our knowing God but God's knowing us, which is grounded in love, not gnosis. The passive ἔγνωσται relocates the initiative to God.
εἰifconjunction (first-class condition)
δέbutadversative conjunction
τιςanyoneNominativesubject (indefinite pronoun)
ἀγαπᾷlovesPres Act Indic 3 Sg · ἀγαπάωmain verb (protasis)→ customary presentἀγαπάω: 'love'; the cognate verb of ἀγάπη (v.1) — love for God is the real index of relationship to him.
τὸνtheAccusativearticle
θεόνGodAccusativedirect objectθεός: God; the proper object of love — contrasted with the τι ('something') one merely claims to know in v.2.
οὗτοςthis oneNominativesubject (resumptive demonstrative)
ἔγνωσταιis knownPerf Pass Indic 3 Sg · γινώσκωmain verb (apodosis)→ intensive perfect (abiding state)γινώσκω (pass.): 'be known'; the perfect passive — to be acknowledged/chosen by God (cf. the Hebrew 'know' of election, Gal 4:9).
ὑπ'bypreposition + genitive (agency)
αὐτοῦhimGenitivegenitive of agency (object of ὑπό)
4

Περὶ τῆς βρώσεως οὖν τῶν εἰδωλοθύτων οἴδαμεν ὅτι οὐδὲν εἴδωλον ἐν κόσμῳ, καὶ ὅτι οὐδεὶς θεὸς εἰ μὴ εἷς.

Concerning, then, the eating of things sacrificed to idols: we know that an idol is nothing in the world, and that there is no God but one.

Resumption of topicοὖνοὖν resumes the question of v.1 after the corrective digression, restating the shared monotheistic premises Paul grants the 'strong' — the foundation he will both affirm (vv.5–6) and qualify (vv.7ff).
Περὶconcerningpreposition + genitive (reference)
τῆςtheGenitivearticle
βρώσεωςeatingGenitiveobject of Περίβρῶσις: 'eating, food'; the action-noun narrows the topic from idol-meat in general to the act of consuming it.
οὖνtheninferential/resumptive conjunctionοὖν: 'therefore, then'; here resumptive — picking up the thread after vv.2–3.
τῶνtheGenitivearticle
εἰδωλοθύτωνthings sacrificed to idolsGenitiveobjective genitive (of βρώσεως)εἰδωλόθυτον: the idol-meat (see v.1); here the object eaten.
οἴδαμενwe knowPerf Act Indic 1 Pl · οἶδαmain verb→ intensive perfect (present sense)οἶδα: again 'we know' — introducing the agreed dogmatic content (vv.4b).
ὅτιthatconjunction (content of οἴδαμεν)
οὐδὲνnothingNominativepredicate nominativeοὐδείς: 'no one, nothing'; here neuter — the idol has no real existence corresponding to it.
εἴδωλονidolNominativesubject (verbless clause)εἴδωλον: 'image, idol' (from εἶδος, 'form'); in LXX/NT the false god's representation — and, the slogan says, a mere nothing.
ἐνinpreposition + dative (sphere)
κόσμῳworldDativedat. of sphereκόσμος: 'world'; the idol corresponds to no reality in the created order.
καὶandcoordinating conjunction
ὅτιthatconjunction (second content clause)
οὐδεὶςnoNominativeattributive (negates θεός)οὐδείς: 'no one'; here adjectival — 'no God.'
θεὸςGodNominativesubject (verbless clause)θεός: God; the Shema's monotheism (Deut 6:4) is the bedrock of the argument.
εἰexceptconjunction (with μή = 'except')
μὴnotnegative (εἰ μή = 'except')εἰ μή: 'except, but'; the exceptive idiom isolating the one true God.
εἷςoneNominativepredicate (substantival numeral)εἷς: 'one'; the cardinal of the Shema — 'the LORD is one' — programmatic for v.6.
5

καὶ γὰρ εἴπερ εἰσὶν λεγόμενοι θεοὶ εἴτε ἐν οὐρανῷ εἴτε ἐπὶ γῆς, ὥσπερ εἰσὶν θεοὶ πολλοὶ καὶ κύριοι πολλοί,

For even if there are so-called gods, whether in heaven or on earth — as indeed there are many gods and many lords —

Concessive groundκαὶ γὰρκαὶ γάρ introduces a concession that sets up the contrast of v.6: granting the existence of many alleged deities and powers, Paul will nonetheless confess one God and one Lord. The protasis hangs, completed by ἀλλ' in v.6.
καὶevenadverbial (with γάρ)
γὰρforexplanatory conjunctionκαὶ γάρ: 'for even / for indeed'; grounds the monotheistic claim by way of concession.
εἴπερif indeedconjunction (concessive condition)εἴπερ: 'if indeed, even if'; the -περ intensifies — granting the premise for argument's sake.
εἰσὶνthere arePres Act Indic 3 Pl · εἰμίmain verb (protasis)→ stative presentεἰμί: 'be, exist'; existence here in the sense of being 'so-called.'
λεγόμενοιso-calledPres Pass Ptc · Nom Pl Masc · λέγωattributive participle→ present (general)λέγω (pass.): 'be called/named'; 'so-called gods' — named such by others, not real deities.
θεοὶgodsNominativesubjectθεός: here plural of the pagan pantheon — gods only in name.
εἴτεwhethercorrelative conjunctionεἴτε … εἴτε: 'whether … or'; distributes the alleged deities across the cosmos.
ἐνinpreposition + dative (place)
οὐρανῷheavenDativedat. of placeοὐρανός: 'heaven, sky'; the celestial deities (sun, stars, astral powers).
εἴτεorcorrelative conjunction
ἐπὶonpreposition + genitive (place)
γῆςearthGenitiveobject of ἐπί (place)γῆ: 'earth, land'; the terrestrial deities and cultic powers.
ὥσπερas indeedcomparative conjunction (confirmatory)ὥσπερ: 'just as'; here confirms that such 'gods and lords' do abound in the religious world.
εἰσὶνthere arePres Act Indic 3 Pl · εἰμίmain verb→ stative present
θεοὶgodsNominativesubject
πολλοὶmanyNominativeattributive adjectiveπολύς: 'many'; the polytheistic plurality contrasted with the εἷς of v.4.
καὶandcoordinating conjunction
κύριοιlordsNominativesubject (coordinate)κύριος: 'lord'; cultic 'lords' (e.g. mystery-cult deities), anticipating the one κύριος of v.6.
πολλοίmanyNominativeattributive adjective
6

ἀλλ' ἡμῖν εἷς θεὸς ὁ πατήρ, ἐξ οὗ τὰ πάντα καὶ ἡμεῖς εἰς αὐτόν, καὶ εἷς κύριος Ἰησοῦς Χριστός, δι' οὗ τὰ πάντα καὶ ἡμεῖς δι' αὐτοῦ.

yet for us there is one God, the Father, from whom are all things and we for him, and one Lord, Jesus Christ, through whom are all things and we through him.

Adversative climaxἀλλ'The strong adversative completes the concession of v.5 with the Christian confession — a binitarian reshaping of the Shema (Deut 6:4): the one God is the Father (source and goal), the one Lord is Jesus Christ (mediator), 'all things' and 'we' running through both. This is the chapter's theological anchor.
ἀλλ'yetstrong adversative conjunctionἀλλά: 'but, yet'; the decisive contrast — over against the many, the Christian 'one.'
ἡμῖνfor usDativedat. of possession/advantage (fronted)
εἷςoneNominativepredicate (numeral, verbless)εἷς: 'one'; the Shema's confession applied to the Father.
θεὸςGodNominativesubjectθεός: God; defined appositionally as 'the Father.'
theNominativearticle
πατήρFatherNominativeapposition to θεόςπατήρ: 'Father'; identifies the one God specifically as the Father — source and goal of all.
ἐξfrompreposition + genitive (source)
οὗwhomGenitiverelative pronoun (object of ἐξ)
τὰtheNominativearticle
πάνταall thingsNominativesubject (verbless; 'are')πᾶς: τὰ πάντα = 'the universe, all things'; creation as a whole derives from the Father.
καὶandcoordinating conjunction
ἡμεῖςweNominativesubject (emphatic pronoun)
εἰςforpreposition + accusative (goal)
αὐτόνhimAccusativeobject of εἰς (goal)αὐτός: refers to the Father — believers exist 'for him' as their telos.
καὶandcoordinating conjunction
εἷςoneNominativepredicate (numeral, verbless)εἷς: 'one'; now of the Lord — κύριος from the Shema applied to Christ.
κύριοςLordNominativesubjectκύριος: 'Lord'; the LXX name of YHWH now confessed of Jesus — a remarkable christological reading of the Shema.
ἸησοῦςJesusNominativeapposition to κύριος
ΧριστόςChristNominativeapposition
δι'throughpreposition + genitive (agency/means)
οὗwhomGenitiverelative pronoun (object of διά)
τὰtheNominativearticle
πάνταall thingsNominativesubject (verbless; 'are')πᾶς: all things came to be 'through' Christ — his mediatorial role in creation (cf. Col 1:16; Jn 1:3).
καὶandcoordinating conjunction
ἡμεῖςweNominativesubject (emphatic pronoun)
δι'throughpreposition + genitive (agency)
αὐτοῦhimGenitiveobject of διά (agency)αὐτός: refers to Christ — our new existence/redemption is mediated through him.
7

Ἀλλ' οὐκ ἐν πᾶσιν ἡ γνῶσις· τινὲς δὲ τῇ συνηθείᾳ ἕως ἄρτι τοῦ εἰδώλου ὡς εἰδωλόθυτον ἐσθίουσιν, καὶ ἡ συνείδησις αὐτῶν ἀσθενὴς οὖσα μολύνεται.

But this knowledge is not in everyone; rather some, through their habituation to the idol until now, eat the food as actually sacrificed to an idol, and their conscience, being weak, is defiled.

Qualification / counterpointἈλλ'The pivot: the confession of v.6 is true, but not everyone holds it experientially. For the 'weak,' long conditioned by paganism, the meat is still felt to be idol-food, and eating it defiles a conscience not yet free. Knowledge alone cannot reach them.
Ἀλλ'butstrong adversative conjunctionἀλλά: 'but'; turns from the shared dogma to its uneven reception.
οὐκnotnegative particle
ἐνinpreposition + dative (sphere)
πᾶσινeveryoneDativeobject of ἐν (substantival adj.)πᾶς: 'all'; 'not in all' — the knowledge is not universally internalized.
theNominativearticle
γνῶσιςknowledgeNominativesubject (verbless; 'is')γνῶσις: the monotheistic insight of vv.4–6 — possessed in theory but not lived by all.
τινὲςsomeNominativesubject (indefinite pronoun)
δὲandconjunction (continuative)
τῇtheDativearticle
συνηθείᾳby habituationDativedat. of means/causeσυνήθεια: 'custom, habituation' (σύν + ἦθος); long-ingrained pagan habit still shapes their perception of the meat.
ἕωςuntilpreposition/adverb (time)
ἄρτιnowadverb (time)ἄρτι: 'just now, at present'; ἕως ἄρτι = 'until now' — the conditioning persists into their Christian present.
τοῦtheGenitivearticle
εἰδώλουof the idolGenitiveobjective genitive (of συνηθείᾳ)εἴδωλον: 'idol'; their accustomedness 'to the idol' — i.e. to idol-worship and its food.
ὡςascomparative particle (manner)ὡς: here 'as being' — they regard the food as genuinely idol-meat.
εἰδωλόθυτονidol-sacrificeAccusativeobject/predicate ('as idol-food')εἰδωλόθυτον: the idol-meat — for the weak it remains charged with cultic meaning.
ἐσθίουσινthey eatPres Act Indic 3 Pl · ἐσθίωmain verb→ customary presentἐσθίω: 'eat'; the disputed act, here done with a divided conscience.
καὶandcoordinating conjunction (result)
theNominativearticle
συνείδησιςconscienceNominativesubjectσυνείδησις: 'conscience' (σύν + οἶδα, 'co-knowledge'); the inner moral awareness that judges one's own act — a key term in 8–10.
αὐτῶνtheirGenitivegenitive of possession
ἀσθενὴςweakNominativepredicate adj. (with οὖσα)ἀσθενής: 'weak, without strength'; the 'weak' conscience lacks the firmness that knowledge would give — the chapter's pastoral focus.
οὖσαbeingPres Act Ptc · Nom Sg Fem · εἰμίcausal/concessive participle→ present (concurrent)εἰμί: the participle gives the ground — 'because it is weak' — for the defilement that follows.
μολύνεταιis defiledPres Pass Indic 3 Sg · μολύνωmain verb→ present (resultative)μολύνω: 'stain, defile, soil'; the weak conscience is contaminated by acting against its own conviction.
8

βρῶμα δὲ ἡμᾶς οὐ παραστήσει τῷ θεῷ· οὔτε ἐὰν μὴ φάγωμεν ὑστερούμεθα, οὔτε ἐὰν φάγωμεν περισσεύομεν.

But food will not commend us to God; we are neither worse off if we do not eat, nor better off if we do eat.

Concession (adiaphora)δὲA balancing concession to the strong: in itself food is morally indifferent — it neither advances nor diminishes our standing before God. The very neutrality of the matter, however, becomes the basis for surrendering one's 'right' (v.9).
βρῶμαfoodNominativesubject (fronted)βρῶμα: 'food'; the concrete thing eaten — here weighed for its (lack of) spiritual value.
δὲbutconjunction (mild contrast)
ἡμᾶςusAccusativedirect object (fronted)
οὐnotnegative particle
παραστήσειwill commend / presentFut Act Indic 3 Sg · παρίστημιmain verb→ gnomic futureπαρίστημι: 'present, bring near, commend'; food does not 'present' us favorably before God — gnomic future of a general truth.
τῷtheDativearticle
θεῷto GodDativedat. of relation (before God)θεός: God; the standing in view is one's acceptance before him, untouched by diet.
οὔτεneithercorrelative negative conjunctionοὔτε … οὔτε: 'neither … nor'; balances the two cases of eating and abstaining.
ἐὰνifconjunction (third-class condition)
μὴnotnegative particle
φάγωμενwe eatAor Act Subj 1 Pl · ἐσθίωverb (protasis)→ constative aorist (subjunctive)ἐσθίω: 'eat' (suppletive aorist φαγεῖν); the case of abstaining.
ὑστερούμεθαare we worse offPres Pass Indic 1 Pl · ὑστερέωmain verb (apodosis)→ stative presentὑστερέω: 'lack, fall short, be worse off'; abstaining costs us nothing before God.
οὔτεnorcorrelative negative conjunction
ἐὰνifconjunction (third-class condition)
φάγωμενwe eatAor Act Subj 1 Pl · ἐσθίωverb (protasis)→ constative aorist (subjunctive)ἐσθίω: the case of eating.
περισσεύομενare we better offPres Act Indic 1 Pl · περισσεύωmain verb (apodosis)→ stative presentπερισσεύω: 'abound, have surplus, be better off'; eating gains us nothing — the matter is truly indifferent.
9

βλέπετε δὲ μή πως ἡ ἐξουσία ὑμῶν αὕτη πρόσκομμα γένηται τοῖς ἀσθενέσιν.

But take care that this right of yours does not somehow become a stumbling block to the weak.

Exhortation (turn to application)δὲThe hinge from premise to pastoral demand: precisely because food is indifferent, the 'right' to eat must be subordinated to the brother's welfare. βλέπετε issues the first imperative of the section.
βλέπετεtake carePres Act Impv 2 Pl · βλέπωmain verb (imperative)→ imperatival present (general precept)βλέπω: 'see, look'; idiomatic 'watch out, beware' when followed by μή — a vigilant warning.
δὲbutconjunction (transitional)
μήlestnegative (introduces caution clause)μή πως: 'lest somehow'; the apprehensive construction warning of a possible bad outcome.
πωςsomehowparticle (indefinite)
theNominativearticle
ἐξουσίαright / authorityNominativesubjectἐξουσία: 'authority, freedom, right'; the strong's legitimate liberty to eat — a key word Paul will probe in ch. 9.
ὑμῶνyourGenitivegenitive of possession
αὕτηthisNominativedemonstrative (attributive)
πρόσκομμαstumbling blockNominativepredicate nominative (of γένηται)πρόσκομμα: 'obstacle, occasion of stumbling' (πρός + κόπτω, 'strike against'); what trips the weak into sin (cf. Rom 14:13).
γένηταιbecomeAor Mid Subj 3 Sg · γίνομαιverb (μή-clause, subjunctive)→ ingressive aoristγίνομαι: 'become'; the feared result — the right turning into a snare.
τοῖςto theDativearticle
ἀσθενέσινweakDativedat. of disadvantage (substantival adj.)ἀσθενής: 'weak'; the brothers whose consciences are unsettled (v.7) — those endangered by the strong's liberty.
10

ἐὰν γάρ τις ἴδῃ σὲ τὸν ἔχοντα γνῶσιν ἐν εἰδωλείῳ κατακείμενον, οὐχὶ ἡ συνείδησις αὐτοῦ ἀσθενοῦς ὄντος οἰκοδομηθήσεται εἰς τὸ τὰ εἰδωλόθυτα ἐσθίειν;

For if someone sees you, the one who has knowledge, reclining at table in an idol's temple, will not his conscience, since he is weak, be 'built up' so as to eat the things sacrificed to idols?

Ground (scenario)γάργάρ supplies the concrete danger behind v.9: the weak brother, seeing the 'knower' at a temple banquet, is emboldened against his own conviction. Paul ironically borrows οἰκοδομηθήσεται ('built up') — the very edification of v.1 — to name a destructive 'building.'
ἐὰνifconjunction (third-class condition)
γάρforexplanatory conjunction
τιςsomeoneNominativesubject (indefinite pronoun)
ἴδῃseesAor Act Subj 3 Sg · ὁράωverb (protasis)→ constative aorist (subjunctive)ὁράω: 'see' (suppletive aorist εἶδον); the public visibility of the act is decisive.
σὲyouAccusativedirect object
τὸνthe (one)Accusativearticle (substantizes ptc.)
ἔχονταhavingPres Act Ptc · Acc Sg Masc · ἔχωattributive participle (apposition to σέ)→ present (general)ἔχω: 'have'; 'the one who has knowledge' — the strong believer addressed directly.
γνῶσινknowledgeAccusativeobject of ἔχονταγνῶσις: the very 'knowledge' of v.1 — now seen to imperil others.
ἐνinpreposition + dative (place)
εἰδωλείῳan idol's templeDativedat. of placeεἰδωλεῖον: 'idol-temple'; the pagan sanctuary whose dining rooms hosted cultic banquets — the most provocative setting.
κατακείμενονreclining (at table)Pres Mid Ptc · Acc Sg Masc · κατάκειμαιcomplementary/circumstantial participle (of ἴδῃ)→ present (concurrent)κατάκειμαι: 'lie down, recline'; the posture of dining at a banquet — i.e. participating in the temple feast.
οὐχὶnotinterrogative negative (expects 'yes')οὐχί: emphatic 'not'; introduces a question anticipating an affirmative answer.
theNominativearticle
συνείδησιςconscienceNominativesubjectσυνείδησις: 'conscience' (see v.7); here it is wrongly 'emboldened' against its own judgment.
αὐτοῦhisGenitivegenitive of possession
ἀσθενοῦςweakGenitivepredicate adj. (in gen. absolute)ἀσθενής: 'weak'; the genitive-absolute gives the circumstance — 'since he is weak.'
ὄντοςbeingPres Act Ptc · Gen Sg Masc · εἰμίgenitive absolute (causal)→ present (concurrent)εἰμί: the participle of the genitive absolute — 'he being weak.'
οἰκοδομηθήσεταιwill be built upFut Pass Indic 3 Sg · οἰκοδομέωmain verb (apodosis)→ predictive future (ironic)οἰκοδομέω: 'build up'; sardonically — an 'edification' that in fact emboldens to ruin, inverting v.1.
εἰςso aspreposition + articular inf. (result/purpose)
τὸthearticle (with infinitive)
τὰtheAccusativearticle
εἰδωλόθυταthings sacrificed to idolsAccusativeobject of ἐσθίεινεἰδωλόθυτον: the idol-meat (see v.1) — what the emboldened conscience now consents to eat.
ἐσθίεινto eatPres Act Inf · ἐσθίωarticular infinitive (of result)→ customary presentἐσθίω: 'eat'; the infinitive states the outcome — eating against conscience.
11

ἀπόλλυται γὰρ ὁ ἀσθενῶν ἐν τῇ σῇ γνώσει, ὁ ἀδελφὸς δι' ὃν Χριστὸς ἀπέθανεν.

For the weak person is destroyed by your knowledge — the brother for whom Christ died.

Consequence (the stakes)γάρThe grave outcome stated baldly: knowledge, severed from love, destroys. The appositional 'the brother for whom Christ died' sets the weak one's eternal worth against the trivial liberty being defended.
ἀπόλλυταιis destroyedPres Mid/Pass Indic 3 Sg · ἀπόλλυμιmain verb (fronted)→ present (progressive/result)ἀπόλλυμι: 'destroy, ruin, perish'; spiritual ruin — the antithesis of being 'built up' (v.10).
γὰρforexplanatory conjunction
the (one)Nominativearticle (substantizes ptc.)
ἀσθενῶνweak onePres Act Ptc · Nom Sg Masc · ἀσθενέωsubstantival participle (subject)→ present (general)ἀσθενέω: 'be weak'; the participle names the endangered brother — 'the one who is weak.'
ἐνbypreposition + dative (means/cause)
τῇtheDativearticle
σῇyourDativepossessive adjectiveσός: 'your' (sg.); pointedly individual — your private knowledge wreaks this ruin.
γνώσειknowledgeDativedat. of means/causeγνῶσις: the boasted 'knowledge' (v.1) — now the very instrument of a brother's destruction.
theNominativearticle
ἀδελφὸςbrotherNominativeapposition to ὁ ἀσθενῶνἀδελφός: 'brother'; the family bond makes the harm a betrayal of kin, not a mere policy difference.
δι'forpreposition + accusative (cause/sake)
ὃνwhomAccusativerelative pronoun (object of διά)
ΧριστὸςChristNominativesubject (rel. clause)Χριστός: the measure of the brother's value — Christ's own death was for him.
ἀπέθανενdiedAor Act Indic 3 Sg · ἀποθνῄσκωmain verb (rel. clause)→ constative aoristἀποθνῄσκω: 'die'; the atoning death — the gravest possible counterweight to a meal.
12

οὕτως δὲ ἁμαρτάνοντες εἰς τοὺς ἀδελφοὺς καὶ τύπτοντες αὐτῶν τὴν συνείδησιν ἀσθενοῦσαν εἰς Χριστὸν ἁμαρτάνετε.

And so, sinning against the brothers and wounding their weak conscience, you sin against Christ.

Inference (theological gravity)δὲThe argument's verdict: harming the weak brother is no minor lapse but sin against Christ himself — for the brother is one with whom Christ has identified (v.11). The two participles specify the offense; the main verb names its true object.
οὕτωςsoadverb (manner, resumptive)οὕτως: 'thus, in this way'; gathers up the scenario of vv.10–11 into a general verdict.
δὲandconjunction (inferential/continuative)
ἁμαρτάνοντεςsinningPres Act Ptc · Nom Pl Masc · ἁμαρτάνωcircumstantial participle (means/temporal)→ present (concurrent)ἁμαρτάνω: 'sin, miss the mark'; the deed is named sin, not mere indiscretion.
εἰςagainstpreposition + accusative (disadvantage)
τοὺςtheAccusativearticle
ἀδελφοὺςbrothersAccusativeobject of εἰςἀδελφός: 'brother'; the offense is against fellow members of Christ's family.
καὶandcoordinating conjunction
τύπτοντεςwounding / strikingPres Act Ptc · Nom Pl Masc · τύπτωcircumstantial participle (coordinate)→ present (concurrent)τύπτω: 'strike, beat'; a violent metaphor — to 'batter' the tender conscience of the weak.
αὐτῶνtheirGenitivegenitive of possession
τὴνtheAccusativearticle
συνείδησινconscienceAccusativeobject of τύπτοντεςσυνείδησις: 'conscience' (see v.7); the vulnerable faculty that the strong's example assaults.
ἀσθενοῦσανbeing weakPres Act Ptc · Acc Sg Fem · ἀσθενέωattributive participle (of συνείδησιν)→ present (state)ἀσθενέω: 'be weak'; the conscience precisely in its weakness is wounded.
εἰςagainstpreposition + accusative (disadvantage)
ΧριστὸνChristAccusativeobject of εἰς (the true victim)Χριστός: the climactic object — to sin against his own is to sin against him (cf. Mt 25:40; Acts 9:4).
ἁμαρτάνετεyou sinPres Act Indic 2 Pl · ἁμαρτάνωmain verb→ customary presentἁμαρτάνω: 'sin'; repeated from the participle to land the indictment — against Christ himself.
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διόπερ εἰ βρῶμα σκανδαλίζει τὸν ἀδελφόν μου, οὐ μὴ φάγω κρέα εἰς τὸν αἰῶνα, ἵνα μὴ τὸν ἀδελφόν μου σκανδαλίσω.

Therefore, if food causes my brother to stumble, I will never eat meat again, ever, so that I may not cause my brother to stumble.

Conclusion (personal resolve)διόπερThe emphatic inferential διόπερ ('for this very reason') seals the argument with Paul's own example: the apostle will forgo a lawful liberty permanently rather than imperil a brother — the model of love-governed freedom developed in ch. 9.
διόπερthereforeemphatic inferential conjunctionδιόπερ: 'for this very reason' (διό + intensive -περ); a strengthened 'therefore' drawing the practical conclusion.
εἰifconjunction (first-class condition)
βρῶμαfoodNominativesubject (protasis)βρῶμα: 'food' (see v.8); the indifferent thing, now weighed against a brother.
σκανδαλίζειcauses to stumblePres Act Indic 3 Sg · σκανδαλίζωmain verb (protasis)→ customary presentσκανδαλίζω: 'cause to stumble, trap' (from σκάνδαλον, a trap's trigger); to lead into sin or apostasy.
τὸνtheAccusativearticle
ἀδελφόνbrotherAccusativedirect objectἀδελφός: 'brother'; the personal 'my brother' makes the obligation intimate.
μουmyGenitivegenitive of relationship
οὐnotnegative (with μή = emphatic)
μὴnevernegative (οὐ μή = emphatic denial)οὐ μή: the strongest Greek negation — 'by no means, never'; with the aorist subjunctive it categorically denies.
φάγωI will eatAor Act Subj 1 Sg · ἐσθίωmain verb (apodosis; subjunctive of emphatic denial)→ constative aorist (emphatic negation)ἐσθίω: 'eat'; with οὐ μή = 'I will absolutely not eat.'
κρέαmeatAccusativedirect objectκρέας: 'meat, flesh'; the plural κρέα of butchered meat — Paul renounces it altogether, not merely idol-meat.
εἰςforpreposition + accusative (time/extent)
τὸνtheAccusativearticle
αἰῶναage / everAccusativeobject of εἰς (extent of time)αἰών: 'age'; εἰς τὸν αἰῶνα = 'forever, for all time' — the renunciation is unconditional in duration.
ἵναso thatconjunction (purpose)
μὴnotnegative (in purpose clause)
τὸνtheAccusativearticle
ἀδελφόνbrotherAccusativedirect object (of σκανδαλίσω)ἀδελφός: 'brother'; the goal of the renunciation — sparing the brother.
μουmyGenitivegenitive of relationship
σκανδαλίσωI cause to stumbleAor Act Subj 1 Sg · σκανδαλίζωverb (purpose clause, subjunctive)→ ingressive aoristσκανδαλίζω: 'cause to stumble' (see above); the very thing love refuses to risk.