Many of Jesus’ disciples said “This is a difficult teaching! Who can understand it?” after they heard this.
Jesus knew that his disciples were complaining about this teaching, so he asked them “Are you offended by this? What would you think if you saw the Son of Man returning to heaven? The Holy Spirit gives life. There is nothing to be gained from the flesh. What I have spoken to you is spirit, and is life. But some of you don’t believe.”
Jesus knew from the start who would believe and which one would betray him.
He said “This is what I meant when I told you that only those who the Father calls can come to me.”
Many of his disciples left at this point and no longer followed him. Jesus then said to the Twelve “Are you going to leave too?”
Simon Peter answered “Who would we go to, Lord? Your words contain the way of eternal life. We now believe in our hearts and know that you are the Messiah, the Holy One of God!”
Jesus replied “I chose you Twelve, yet one of you is full of darkness.” He was speaking about Judas, the son of Simon Iscariot, one of the twelve disciples, because he was going to betray Jesus.