The Catechism in Questions & Answers

256. Are there examples of election in the New Testament?

From among His disciples, Jesus elected the Apostles and sent them into all the world with the commission to teach and baptise. Thus the election of the people of God is no longer limited to Israel, but incorporates all those who believe in Jesus, whether Jew or Gentile. Thus the people of the new covenant has been chosen by God (cf. 1 Peter 2: 9).
Peter was elected to a special function in the church, namely the Petrine office.

Petrine office: see explanation of Question 457.

Since Old Testament times, all non-Israelite nations were designated as “Gentiles”. These were people who did not serve the God of Abraham, but rather served other gods. Even in New Testament times, non-Jews were designated as Gentiles, whether or not they had been baptised.