408th Post Jesus Said On His Rejection and Death Con't. - John 13:21.

John 13: 21.
Most assuredly, I say to you, one of you will betray Me.
Spoken by Jesus the night He was to be betrayed. Here again, we have proof that Jesus was more than just a man. If Jesus was only a man, how would He know that someone would betray Him, and that He knew who that person was who would do it; and then allow it to happen. A regular man would try to preserve his life and foil the attempt, if he knew before hand it was to happen. Jesus being God, knew the big picture; and knew His life was part of the plan. Jesus told His disciples, so that when it happens, and later when they thought about the events and how they unfolded. They would remember that Jesus told them He would be betrayed before the event actually happened.
Jesus knew that His disciples still did not believe that He was the Son of God. He did everything in His power to prove to them that He is the Promised Messiah. We should remember this when we are out trying to witness to others for Christ. If the disciples had a hard time believing, and they witnessed the miracles and teachings, how much more should we have understanding when people do not believe us. God opens the hearts of unbelievers not us, or our message. We need to get the message out. That is our job.