The proof

In John 10, the Jewish leaders said, "If you are the Messiah, tell us plainly."

Jesus said, "The proof is what I do in the name of my Father."

The Jews considered Jesus to be a blasphemer because of his claims of kinship with God, even though they saw (were witnesses to) or heard about the miracles performed in God's name. None of his works mattered to them because they saw Jesus only as a man, son of Joseph and Mary. They did not remember the miracle birth. They had forgotten all the prophecies foretold in Isaiah.