The truth to Nicodemus

 "You, Nicodemus, are a teacher of Israel, and yet you don't know these things? We tell you of the things we have seen and of the things we have heard and yet you do not believe our testimonies. If you won't believe when we tell you the things pertaining to earth, how much more will you disbelieve when we tell you of the things pertaining to the heavens?"

For this reason...our failure to believe...all things come in the way of parables, especially the things pertaining to heaven. My opinion.