Where in the Bible does it talk about Paul becoming a Christian?

Acts 9, Acts 22, and Acts 26.

Please read Acts 9:3-8 King James Version (KJV)

3 And as he journeyed, he came near Damascus: and suddenly there shined round about him a light from heaven:4 And he fell to the earth, and heard a voice saying unto him, Saul, Saul, why persecutest thou me? 5 And he said, Who art thou, Lord? And the Lord said, I am Jesus whom thou persecutest: it is hard for thee to kick against the pricks.

6 And he trembling and astonished said, Lord, what wilt thou have me to do? And the Lord said unto him, Arise, and go into the city, and it shall be told thee what thou must do.

7 And the men which journeyed with him stood speechless, hearing a voice, but seeing no man.

8 And Saul arose from the earth; and when his eyes were opened, he saw no man: but they led him by the hand, and brought him into Damascus.

Acts.

Luke wrote the book called "Acts". The Muratorian Canon (circa A.D. 170) explicitly names Luke a the author. Eusebius (c. 325) lists numerous sources that show Luke to have written about Paul before he became a Christian, how Paul became a Christian, and what Paul did once he'd had his Damascus road experience of the risen Christ.

The first mention of him is when he was known as Saul of Tarsus, and he approvingly looked on as the Christian, Stephen, was being stoned to death by religious zealots (of which Saul was foremost). That's in Acts chapter 7 verses 54 through to 8:3. Saul led a vicious persecution against the new Christians. Go to chapter 9, read through to verse 31, then go to 12:21 and read through to the end of chapter 28 and learn how he was converted to Christ and lived to his dying day as a witness for Christ.

You can also read Paul's own account, written by himself, in 1st Corinthians chapter 15 verse 3 to verse 11.

Acts. Read for yourself

Paul was a Jewish legal expert. A sort of officer of that ancient law. Then his conversion while on his way to Damascus happened, and he had some time to think about it, he was blinded by the experience. He decided to dedicate himself to God as does anyone who is convinced that God is the Lord of their life.

Read Acts 9 and 17.

Death leads to heaven or hell, and the only way to get to heaven is to trust in Jesus Christ as your Savior. Jesus loves us so much that He died on the cross to pay the complete price for our sins and came back from the dead (1 Cor. 15:3-4). He promises everlasting life as a free gift to anyone who simply believes in Him for it!

In the book he wrote, Acts.

Rather a coincidence, I think.