“But  there are some of you who do not believe.”

Therefore many of His disciples, when they heard this, said, “This is a hard saying; who can understand it?” When Jesus knew in Himself that His disciples complained about this, He said to them, “Does this  offend you? What then if you should see the Son of Man ascend where He was before? It is the Spirit who gives life; the  flesh profits nothing. The  words that I speak to you are spirit, and they are life. But  there are some of you who do not believe.” For Jesus knew from the beginning who they were who did not believe, and who would betray Him. And He said, “Therefore  I have said to you that no one can come to Me unless it has been granted to him by My Father.” From that time many of His disciples went back and walked with Him no more. Then Jesus said to the twelve, “Do you also want to go away?” But Simon Peter answered Him, “Lord, to whom shall we go? You have the words of eternal life. Also we have come to believe and know that You are the Christ, the Son of the living God.” Jesus answered them, “Did I not choose you, the twelve,  and one of you is a devil?” He spoke of Judas Iscariot, the son of Simon, for it was he who would betray Him, being one of the twelve. After these things Jesus walked in Galilee; for He did not want to walk in Judea, because the Jews sought to kill Him. Now the Jews’ Feast of Tabernacles was at hand. His brothers therefore said to Him, “Depart from here and go into Judea, that Your disciples also may see the works that You are doing.
John 6:60-7:3 - NKJV