This post is an exercise in following the train of logic that runs through a Pauline argument.
In Galatians 3:1, Paul blames the Galatians for forgetting that Christ had been crucified:
ἀνόητοι Γαλάται, τίς ὑμᾶς ἐβάσκανεν, οἷς κατ’ ὀφθαλμοὺς Ἰησοῦς Χριστὸς προεγράφη ἐσταυρωμένος;
“O foolish Galatians, who has bewitched you, before whose eyes Jesus the Messiah was previously depicted as having been crucified?”
This verse is crucial (hah!) for understanding what the “Galatian heresy” was – and yet many widespread understandings of the Galatian heresy do not make any sense of it. For it is clear from Paul’s shock and surprise that he thinks there is an obvious contradiction between Christ’s death on the cross and the Galatians’ error.
Suppose that the Galatians did not believe in the imputation of Christ’s active obedience, or substitutionary atonement. What would follow about eating with Gentiles? Very little, it seems to me. God could reckon believing Gentiles righteous and reckon believing Jews righteous without requiring them to eat together. After all, there had been righteous Gentiles before, and righteous Jews before, and God kept them separate. From the fact that individuals are righteous, nothing whatever follows about eating together. If the core of the gospel is imputation, then it is hard to see how the Galatians’ practice of prandial apartheid tells against it at all.
Again, suppose that the problem with the Galatians was that they were trying to add obedience to faith instead of leaving it alone in all its pure, utterly inert loneliness so that it could “rest and receive” Christ’s imputed righteousness. OK, let’s straighten them out about this. What would it entail for eating with Gentiles? Again, I don’t see how it would make any difference. If the whole point is that we need to avoid bringing our works (“filthy rags” etc.) before God’s judgment seat and must rely only on Christ, then there doesn’t seem to be any reason the Jews and Gentiles couldn’t do that in separate rooms. Their eating apart from each other does’t contradict sola fide at all. Separate but equal, right?
No, Paul says that they are at odds with the truth that Christ was crucified. And if we turn to Ephesians 2, we can find a clear explanation of what the cross did:
Therefore remember that you, once Gentiles in the flesh—who are called Uncircumcision by what is called the Circumcision made in the flesh by hands— 12 that at that time you were without Christ, being aliens from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world. 13 But now in Christ Jesus you who once were far off have been brought near by the blood of Christ.
14 For He Himself is our peace, who has made both one, and has broken down the middle wall of separation, 15 having abolished in His flesh the enmity, that is, the law of commandments contained in ordinances, so as to create in Himself one new man from the two, thus making peace, 16 and that He might reconcile them both to God in one body through the cross, thereby putting to death the enmity.
This is the truth that the Galatians were denying. To keep Gentiles at separate tables was effectively a claim that Christ hadn’t really done what Ephesians 2:14-16 says He did. He did it by being crucified.
This should make us very hesitant to sign onto any system of theology that makes God’s accounting in His head the central act of justification. If what really matters is that Christ’s righteousness becomes mine and my sin becomes his, then the cross is displaced from the central place it occupies in Paul’s doctrine. For the cross does not accomplish these acts of imputation. If they happen at all, they happen after it.