The disciples failed miserably in the Garden of Gethsemane. It was Jesus' last effort to avoid his crucifixion. Jesus told them to stay awake and pray at the risk of their lives. Each time they failed. Because of that disunity, Jesus couldn't continue his mission of becoming accepted as the Messiah and becoming the King of the Jews with a government without end. Instead, he became a sacrificial lamb for Atonement. That was the backup plan, not the primary plan. Then, after being betrayed by Judas, all the disciples ran away or denied their loyalty to Jesus. This was the ultimate betrayal.  Christians haven't done much of a better job the second time around, though, true, there is a "remnant flock."