'Judaism' in the Bible

Phrygia and Pamphylia, Egypt and the districts of Libya around Cyrene, and the visitors from Rome, both Jews and proselytes (Gentile converts to Judaism),

This suggestion pleased the whole group. So they chose Stephen, a man full of faith and the Holy Spirit, Philip, Prochorus, Nicanor, Timon, Parmenas, and Nicolaus, a gentile convert to Judaism from Antioch.

When the meeting of the synagogue broke up, many Jews and devout converts to Judaism followed Paul and Barnabas, who kept talking to them and urging them to continue in the grace of God.

For you have heard about my former way of life in Judaism: I persecuted God’s church to an extreme degree and tried to destroy it.

I advanced in Judaism beyond many contemporaries among my people, because I was extremely zealous for the traditions of my ancestors.

But when I saw that they were not being straightforward about the truth of the gospel, I told Cephas (Peter) in front of everyone, “If you, being a Jew, live [as you have been living] like a Gentile and not like a Jew, how is it that you are [now virtually] forcing the Gentiles to live like Jews [if they want to eat with you]?”

For there are also many rebellious people, full of empty talk and deception, especially those from Judaism.