Acts 22:3 I am a Jew, born in Tarsus in Cilicia, but brought up in this city, educated at the feet of Gamaliel according to the strict manner of the law of our fathers, being zealous for God as all of you are this day.

In Acts 17 Luke writes ‘they came to Thessalonica, where there was a synagogue of the Jews. And Paul went in, as was his custom, and on three Sabbath days he reasoned with them from the Scriptures, explaining and proving that it was necessary for the Christ to suffer and to rise from the dead, and saying, “This Jesus, whom I proclaim to you, is the Christ.”’

Surely Paul, then Saul, did not learn Jesus was the Christ from Gamaliel, so who taught Paul?

Galatians 1:12 For I did not receive it from any man, nor was I taught it, but I received it through a revelation of Jesus Christ.

The Word Himself changed Paul.

According to the Word.

In the beginning was the Word, and the Word was with God, and the Word was God.