Contradiction with Matthew 12:38
This verse contradicts John 2:18 because in Matthew, the scribes and Pharisees are asking for a sign directly from Jesus, who responds saying an evil and adulterous generation seeks a sign, unlike the Jews in John who ask for a sign after the temple cleansing.
Matthew 12:38: Then certain of the scribes and of the Pharisees answered, saying, Master, we would see a sign from thee.
Contradiction with Mark 8:11-12
In this verse, the Pharisees demand a sign from Jesus, and He explicitly refuses to give one, contrasting with John 2:18 where He implies a future sign by mentioning the destruction and raising of the temple.
Mark 8:11-12: And he sighed deeply in his spirit, and saith, Why doth this generation seek after a sign? verily I say unto you, There shall no sign be given unto this generation.
Contradiction with Luke 11:29
Similar to Matthew, this verse records Jesus' response to those who seek a sign, calling them a wicked generation, which contrasts with the dialogue following the request for a sign in John 2:18.
Luke 11:29: And when the people were gathered thick together, he began to say, This is an evil generation: they seek a sign; and there shall no sign be given it, but the sign of Jonas the prophet.
Contradiction with John 6:30
Here, people ask for a sign after previously witnessing miracles, indicating disbelief and contradiction, as John 2:18 implies a forthcoming sign related to Jesus' authority.
John 6:30: They said therefore unto him, What sign shewest thou then, that we may see, and believe thee? what dost thou work?