Contradiction with 2 Kings 20:1
This verse records the illness of King Hezekiah, contradicting the idea that all illnesses and demons can simply be cast out without mention of a necessary divine intervention through prayer and a sign.
2 Kings 20:1: In those days was Hezekiah sick unto death. And the prophet Isaiah the son of Amoz came to him, and said unto him, Thus saith the LORD, Set thine house in order; for thou shalt die, and not live. [Set...: Heb. Give charge concerning thine house]
Contradiction with 2 Timothy 4:20
Paul mentions leaving Trophimus sick in Miletus, suggesting not all sicknesses were cured instantly, contradicting the events described in Matthew 8:16.
2 Timothy 4:20: Erastus abode at Corinth: but Trophimus have I left at Miletum sick.
Contradiction with Mark 9:28-29
Jesus indicates that certain kinds of demons can only be cast out through prayer and fasting, contradicting the immediate healing described in Matthew 8:16.
Mark 9:28-29: And when he was come into the house, his disciples asked him privately, Why could not we cast him out?