Contradiction with James 2:19
This verse acknowledges that demons believe in one God and tremble, as opposed to showing reverence or worship mentioned in Mark 5:7.
James 2:19: Thou believest that there is one God; thou doest well: the devils also believe, and tremble.
Contradiction with Matthew 8:29
This verse depicts demons questioning Jesus about torment before the appointed time, which contradicts the plea for mercy seen in Mark 5:7.
Matthew 8:29: And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time?