John 3:11-13

11Verily, verily, I say unto thee, We speak that which we know, and we bear witness of that which we have seen, and ye receive not our witness.

12If I have said the earthly things to you, and ye believe not, how, if I say the heavenly things to you, will ye believe?

13And no one has gone up into heaven, save he who came down out of heaven, the Son of man who is in heaven.