John 2:18; John 6:30; John 20:29

18 So the Jews said to him, yWhat sign do you show us for doing these things?

30 So they said to him, sThen what sign do you do, that we may see and believe you? What work do you perform?

29 Jesus said to him, Have you believed because you have seen me? tBlessed are those who have not seen and yet have believed.