Jesus and three of the disciples have just had an amazing experience on a mountain. Now they come down to the bottom of the mountain and are faced with the sad reality of Satan at war with humanity, faithlessness of not only a father, but also Jesus's disciples.
We will see that even though our faith can often be imperfect, our perfect Lord and Savior is compassionate to help us in our weakness. Not only that, but we are reminded that prayer builds up our faith.