John 2:18
Then the Jews addressed Him and asked, "What sign can you show us that you have authority to act in this way?"
John 6:30
So they asked Him, "What wonder-work then are you going to perform for us to see and so believe in you? What work are you going to do?
Matthew 12:39
But He answered, "Only a wicked and treacherous age is hankering for a spectacular sign, and no sign will be given it but the sign of the prophet Jonah.
John 10:38
But if I am doing so, even if you will not believe me, believe the deeds, that you may come to know and continue to know that the Father is in union with me and I am in union with the Father."