Why did Peter separate himself from the Gentiles?

Peter separated himself from the Gentiles because he feared the Jewish emissaries who came from James in Jerusalem. Before they arrived, he ate freely with Paul's Gentile converts, but afterward he gave in to fear of those men's disapproval and withdrew, refusing to continue eating with them.

Les explains that before certain men came from James, who was then the headman in Jerusalem, Peter ate with Paul and the Gentile believers regardless of the meal. But after Jewish people came from Jerusalem, Peter became scared and afraid of them. To maintain the testimony of Paul's Gospel of Grace and prove that believers are free from the dietary laws, Paul expected Peter to stand firm. Instead, Peter gave in and refused to eat with Paul's Gentile converts. Paul became upset and called Peter two-faced: when no one from Jerusalem was present, Peter had no problem eating with the Gentiles, but when they came, he acted as a good Jew and withdrew. Paul said Peter separated himself, fearing not God but the men from Jerusalem. Les says he has always given Peter credit.

Galatians 2:12

For before that certain came from James, he did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them which were of the circumcision.

What did Peter do after the Jewish people came from Jerusalem?

After the Jewish people came from Jerusalem, Peter became afraid of them and gave in. He withdrew and separated himself from Paul's Gentile converts, refusing to eat with them. He acted two-faced, eating with Gentiles before but pulling back once the Jerusalem emissaries arrived, fearing the men from Jerusalem rather than God.