He said to him, "Most assuredly, I tell you, hereafter you will see heaven opened, and the angels of God ascending and descending on the Son of Man."

 We have already seen that the Fourth Gospel was written in a situation where it was necessary to make sure that John the Baptist did not occupy an exaggerated position in men's thoughts. So John begins this passage with a saying of John the Baptist which gives to Jesus the first place. 