Contradiction with Matthew 26:69-70
This verse states Peter denied Jesus before a servant girl, differing from John 18:26, which describes a man challenging Peter.
Matthew 26:69-70: But he denied before [them] all, saying, I know not what thou sayest.
Contradiction with Mark 14:66-68
According to this verse, Peter's first denial occurred before a maid of the high priest, contrasting the male servant mentioned in John 18:26.
Mark 14:66-68: And as Peter was beneath in the palace, there cometh one of the maids of the high priest:
Contradiction with Luke 22:56-57
Luke's account states a maid challenged Peter, which varies from John 18:26's narrative involving a male servant.
Luke 22:56-57: But a certain maid beheld him as he sat by the fire, and earnestly looked upon him, and said, This man was also with him.