John 6:63-65

63The Spirit is the one who gives life; human nature is of no help! The words that I have spoken to you are spirit and are life.

64But there are some of you who do not believe.” (For Jesus had already known from the beginning who those were who did not believe, and who it was who would betray him.)

65So Jesus added, “Because of this I told you that no one can come to me unless the Father has allowed him to come.”