Contradiction with 1 Corinthians 1:27
This verse suggests that God uses the weak and foolish things to confound the strong and wise, while Acts 9:22 shows Saul increasing in strength to prove his point.
1 Corinthians 1:27: But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty;
Contradiction with 1 Corinthians 2:1-2
Paul claims to know nothing except Christ crucified and does not rely on eloquence or human wisdom, unlike the powerful proving of Jesus as the Christ in Acts 9:22.
1 Corinthians 2:1-2: And I, brethren, when I came to you, came not with excellency of speech or of wisdom, declaring unto you the testimony of God.