The disciples finally understand what Jesus has been trying to teach and say to them and they realize that He really is from God the Father.
Jesus also tells them that there will soon come a day when they will scatter and deny Him. And even though they will have troubles in the world, Jesus will be with them and give them a peace that passes all understanding which will help them overcome the world.
I John 5:5 "Who is it that overcomes the world? Only the one who belives that Jesus is the Son of God."