they.

Acts 10:9, 45
The next day at about the sixth hour, as the men were approaching the city on their journey, Peter went up on the roof to pray. . . .

Acts 15:1, 5
Then some men came down from Judea and were teaching the brothers, "Unless you are circumcised according to the custom of Moses, you cannot be saved." . . .

Acts 21:20-23
When they heard this, they glorified God. Then they said to Paul, "You see, brother, how many thousands of Jews have believed, and all of them are zealous for the Law. . . .

Galatians 2:12-14
For before certain men came from James, he used to eat with the Gentiles. But when they arrived, he began to draw back and separate himself, for fear of those in the circumcision group. . . .