The Sign Of Jonah And Christ’s Messiahship

If you was asked for proof that Jesus was the Messiah, could you prove it? What would you give for absolute proof? How could you prove that the Jesus of Nazareth was the Messiah? The Jews of His time would not except that he was the Messiah. And they asked Him for proof, and Christ himself gave them evidence that He was the prophesied Messiah to come, what was it?