I wonder what would have become of those faithful believers if Peter held fast to his principles and beliefs that it was all for the Jew, and only for the Jew?
Pray for the peace of Israel and understand that anyone can become "a Jew"--circumcised in the heart, not merely in the flesh. This is by faith, as God promised Abraham, and has nothing to do with the flesh, but God's arms are open to all who will call on the Name of the Lord. It's the promised gift.
When you pray, remember Ishmael and God's promise to bless Him.
"If God be for us [or Ishmael] who can be against us [or Ishmael]?
Read: Romans 4:1-13; 9:1-33; Genesis 15:1-7.