We might not realize it today, but the most intense challenge the first followers of Jesus met was including Gentiles into the people of God, the ecclesia. No, even more challenging was loving those Gentiles. Peter points the way.
We find it in Acts 10 and I see four points (see 40 Days Living the Jesus Creed).

1. Peter learned that other people — seen in this Gentile centurion Cornelius — were seeking God (Acts 10:2): he was a “devout man who feared God” and who “prayed constantly to God.”
2. Peter experienced his own resistance to boundary-crossing. “What God has made clean, you must not call profane” (10:15). Fine and dandy, until you are asked to eat pork.
3. Peter learned that God is impartial. “God has shown me that I should not call anyone profane or unclean” (10:28). And here’s a statement that should give us all some pause: “I truly understand,” Peter reveals, “that God shows no partiality, but in every nation anyone who fears him and does what is right is acceptable to him” (10:34-35).
4. Peter learned that God dwells with all. Peter prayed and the next thing you know — Pentecost, or an extension of Pentecost, happened all over again — “the Holy Spirit fell upon all who heard the word” (10:44).