John 3:11-13

¹¹Verily, verily, I say unto thee, We speak that which we know, and bear witness of that which we have seen; and ye receive not our witness. ¹²If I told you earthly things and ye believe not, how shall ye believe if I tell you heavenly things? ¹³And no one hath ascended into heaven, but he that descended out of heaven, [even] the Son of man, who is in heaven.