A lot happens for the disciples once Peter declares Jesus to be the Messiah. 

It is fascinating to connect this conversation Jesus has with his disciples with the story of the Transfiguration which happens soon afterwards. The preceding healing of a blind man is the only recorded time that Jesus has to touch twice to heal, and it could be a masterful teaching technique. The disciples are confused by their inability to cast an evil spirit out from a young boy, and the explanation Jesus provides is not all that clarifying!