What Does Galatians 2:18 Mean?

For if I build again the things which I destroyed, I make myself a transgressor. The conditional ei gar ha katelysa tauta palin oikodomō (εἰ γὰρ ἃ κατέλυσα ταῦτα πάλιν οἰκοδομῶ, "if the things which I destroyed, these I build again") uses architectural metaphor. The verb katalyō (καταλύω) means to demolish completely, tear down; oikodomeō (οἰκοδομέω) means to build, construct. What did Paul demolish? The system of justification by law-works, the idea that Gentiles must become Jews to be saved, the necessity of circumcision for righteousness.

If Peter rebuilds this demolished system by returning to law-based separation, the result: parabatēn emauton syniστanō (παραβάτην ἐμαυτὸν συνιστάνω, "I establish myself as a transgressor"). Parabatēs (παραβάτης) means law-breaker, transgressor—one who steps across boundaries. The compound verb synistēmi (συνίστημι, "to establish, demonstrate") indicates proving or showing conclusively. By rebuilding the law-system he demolished through the gospel, Peter proves he was wrong either in tearing it down or in rebuilding it—either way, he's a transgressor.

Paul's logic is devastating: there's no neutral middle ground. Either justification is by faith alone, making law-keeping unnecessary for righteousness (so returning to it is transgression against grace), or justification requires law-works, making the gospel itself transgression. Peter's inconsistency doesn't just confuse the issue—it proves him a transgressor regardless of which position is true. Only unwavering commitment to justification by faith alone maintains consistency.