Contradiction with John 18:20
This verse where Jesus says he spoke openly to the world contradicts the limited scope of the disciples of John reporting only a selection of Jesus' works in Luke 7:18.
John 18:20: Jesus answered him, I spake openly to the world; I ever taught in the synagogue, and in the temple, whither the Jews always resort; and in secret have I said nothing.
Contradiction with John 8:32
Contradicts because the followers of John in Luke 7:18 are still uncertain about Jesus' identity, whereas this verse implies knowing the truth brings certainty and freedom.
John 8:32: And ye shall know the truth, and the truth shall make you free.
Contradiction with Matthew 11:3
It contradicts the implied clarity of Jesus’ identity in Luke 7:18, as John’s disciples question if Jesus is the one to come.
Matthew 11:3: And said unto him, Art thou he that should come, or do we look for another?
Contradiction with Mark 9:32
Contradicts as the disciples don't understand Jesus’ message, while in Luke 7:18, there is no indication of misunderstanding by John's disciples.
Mark 9:32: But they understood not that saying, and were afraid to ask him.
Contradiction with Isaiah 35:5
Contradicts by predicting unequivocal signs which imply clarity, while in Luke 7:18, John’s disciples seem unsure about Jesus’ fulfillment of such prophecies.
Isaiah 35:5: Then the eyes of the blind shall be opened, and the ears of the deaf shall be unstopped.