Thomas Aquinas Commentary Galatians 2:17-18

"But if, while we sought to be justified in Christ, we ourselves also were found sinners, is Christ a minister of sin? God forbid. For if I build up again those things which I destroyed, I prove myself a transgressor." — Galatians 2:17-18 (ASV)

After proving from the apostles’ manner of life that the works of the Law should not be observed, the Apostle raises a question to the contrary. In this regard, he does three things:

1. He raises the question.
2. He solves it, saying, God forbid (Galatians 2:17).
3. He explains his solution (Galatians 2:19).

The first point can be developed in two ways, according to a gloss. First, someone could argue that the apostles sinned by abandoning the Law and turning to the faith of Christ. But the Apostle shows that this would lead to the unwelcome conclusion that Christ is the author of sin for calling people to His faith. This is what he means when he says: If we apostles, while we seek to be justified in Him (that is, through Christ), are found to be sinners for leaving the Law, is Christ then the minister of sin? In other words, is He inducing us to sin, the one who called us from the slavery of the Law to His faith? He was made under the law, that he might redeem them that were under the law (Galatians 4:4), namely, from the burden of the Law.

The Apostle answers, God forbid, because Christ is instead the minister of justice: By the obedience of one, many shall be made just (Romans 5:19); Who did no sin, neither was guile found in his mouth (1 Peter 2:22). That Christ is not the minister of sin in leading someone from the Old Law is plain. For if I, by wanting to glory once more in the Law, build up again the things I have destroyed—namely, my prideful glorying in the Law—I make myself a transgressor by taking up what I destroyed. This is like the saying, The dog is returned to his vomit (2 Peter 2:22), or the curse, Cursed be the man that shall raise up and build the city of Jericho (Joshua 6:26).

When he says, which I have destroyed, he does not mean the Law itself, as the Manicheans would claim, because the Law is holy (Romans 7:12). Instead, he means pride in the Law, about which it is said in Romans: For they, seeking to establish their own justice have not submitted themselves to the justice of God (Romans 10:3).

Now, if someone were to object that since Paul formerly destroyed the faith of Christ, he makes himself a transgressor by now trying to build it up, the answer is clear. He did indeed try to destroy the faith of Christ, yet because of the truth, he did not persist, as the Lord said to him: Why persecutest thou me? It is hard for thee to kick against the goad (Acts 9:4). But pride in the Law was futile, and this pride could be destroyed, never to be re-established.

A second way to understand this is to relate the statement, we ourselves are found sinners, not to abandoning the Law (as in the first explanation), but to observing the Law. For it is plain that anyone who seeks to be made just does not profess to be just, but a sinner. The meaning, therefore, is this: If we, in seeking to be justified in Christ, are by that very act found to be sinners because we observed the Law, is Jesus Christ then the minister of sin? In other words, is He commanding people to observe the works of the Law after His passion—something that cannot be done without sin? Note that this explanation aligns with Jerome’s opinion, which held that the legal observances became deadly immediately after the passion of Christ.

A third way to explain we ourselves are found to be sinners is to see it as referring to the state in which the Law was observed. This is not because they sinned by observing the Law, but because the Law is deficient and cannot remove sin. Hence, the meaning is this: If, in seeking to be justified in Christ, we are found to be sinners (that is, still in our sins) because the Law does not remove sin—as stated in Romans, For we have charged both Jews and Greeks, that they are all under sin (Romans 3:9)—is Jesus Christ then the minister of sin, bringing us back to observe a Law under which we remain in sin? This explanation agrees with Augustine’s interpretation.

And Paul answers both explanations with, God forbid, because he destroyed the Law as it was understood carnally by judging and teaching it spiritually. Therefore, if I were to re-establish the observances of the carnal law, I would be a transgressor of the spiritual law.

Furthermore, it can be explained in a fourth way. I have said that a person is not justified by the works of the Law. But someone might say, “Nor by the faith of Christ either,” because many people sin after embracing the faith of Christ. And this is what he means: If we, who seek to be justified in Christ and have become believers, are ourselves found to be sinners by living in sin, is Jesus Christ then a minister of sin and damnation, just as the minister of the Old Law was a minister of sin and damnation?

This is not because the Law led one into sin, but because it was the occasion for sin, for it forbade sin but conferred no grace to help one resist it. Hence it is said, But sin, taking occasion by the commandment, wrought in me all manner of concupiscence (Romans 7:8). But Christ gives helping grace: Grace and truth came by Jesus Christ (John 1:17). Therefore, in no way is He the minister of sin, either directly or as its occasion.