As soon as Judas took the bread, Satan entered into him. So Jesus told him, "What you are about to do, do quickly." John 13:27
This is such a revealing scene! Jesus has just identified the one who was to betray him. Earlier we are told that Jesus knew all along who would betray him. He went so far as to say that this person was of the devil. Instead of condemning Judas, our Lord waits until this time to reveal him and sends him out to do his evil deed.
Why did he send Judas to betray him? Why did Jesus not expel Judas early on? More importantly, we would ask, why would Jesus choose Judas in the first place? He deliberately chose his betrayer that scripture should be fulfilled. For, in the big picture, Judas was necessary for the plan of God to be complete.
Without the betrayal, Jesus would not have been crucified. If Jesus had not died for us, we would bear our sin and condemnation. The plan of God requires evil people and their evil deeds to be accomplished.
But this is to fulfill this passage of Scripture: 'He who shared my bread has turned against me.' (John 13:18).