Oh, that I had someone to hear me! I sign now my defense—let the Almighty answer me; let my accuser put his indictment in writing.
(Job 31:35)
“I sign now my defense” may be translated as: “I put my tau”.
It represents also the end times. Hence the crucifixion may be itself a signature to claim that Jesus, being him crucified, is the Messiah.
Who denied that Jesus is the Christ, not coincidentially, were the same people who claimed that Jesus is not the son of YHWH.
Who is the liar? It is whoever denies that Jesus is the Christ. Such a person is the antichrist--denying the Father and the Son.
(1 John 2:22)
This explains also the strange insistence of Ignatius against the same enemy:
Jesus Christ… was truly born, and ate and drank. He was truly persecuted under Pontius Pilate; He was truly crucified, and [truly] died… He was also truly raised from the dead.
(Trallians 9)
Hence, per Detering, given a Jewish Jesus cult (where Jesus didn't die) and given the presence of Gnostic sects (where Jesus is not the son of YHWH: see the Naassenes),...
...the notion of a “crucified Jesus” (Jesus + crucifixion) was born as reaction of the Jewish factions of the Jesus cult against the Gnostic factions of the same Jesus cult.