John 13: Jesus foresaw

Why the disciples spread the gospel and suffered for it? In the Lord's Supper, Jesus foresaw his betrayal and after that, he said:

19 From now on I am telling you before it happens, so that when it does happen, you may believe that I am He. 20 Truly, truly I say to you, the one who receives anyone I send, receives Me; and the one who receives Me receives Him who sent Me.”

The disciples understood that everything, Judas betrayal included, was under the control of Father and the Son.
Besides, in the Lord's Supper Jesus washed the feet of his disciples, Judas included. As Jesus came from heaven to earth for our sake, so Jesus that should have his feet washed, washed his disciples feet. Peter was very aware that it was weird to have his feet washed by the King, but what did Judas think? Judas judged Jesus when he was worshiped by Mary. An evil guy see bad things even when seeing good things.