Contradiction with Matthew 10:14
While Acts 18:5 describes Paul's commitment to preaching, Matthew 10:14 instructs to leave those who don't listen.
Matthew 10:14: And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet.
Contradiction with Matthew 7:6
Acts 18:5 shows persistence in preaching, whereas Matthew 7:6 advises not to waste efforts on those unreceptive.
Matthew 7:6: Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.
Contradiction with 1 Corinthians 1:17
Acts 18:5 emphasizes preaching the word, but 1 Corinthians 1:17 suggests not all preaching efforts focus on baptism.
1 Corinthians 1:17: For Christ sent me not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect. [words: or, speech]
Contradiction with Acts 9:15-16
While Acts 18:5 speaks of testifying to Jews, Acts 9:15-16 highlights Paul’s broader mission to Gentiles.
Acts 9:15-16: But the Lord said unto him, Go thy way: for he is a chosen vessel unto me, to bear my name before the Gentiles, and kings, and the children of Israel:
Contradiction with 2 Corinthians 4:2
Acts 18:5 shows bold speaking, while 2 Corinthians 4:2 advises against deception in preaching.
2 Corinthians 4:2: But have renounced the hidden things of dishonesty, not walking in craftiness, nor handling the word of God deceitfully; but by manifestation of the truth commending ourselves to every man's conscience in the sight of God. [dishonesty: Gr. shame]