Remember the disciples were terrified when the voice came from the cloud, and they fell to the ground. Next thing that happens though, Jesus is over there telling them not to be scared. As they came down the mountain Jesus told them not to tell anyone of this experience until after his resurrection from the dead.
Some people say that John's gospel is the only one that makes Jesus out to be God because John's focus seems so different from Matthew, Mark and Luke's accounts. Remember that John was one of the three disciples chosen to go on this trip up the mountain. He was an eyewitness to this transfiguration, this white and glowing Jesus. Thus he could vouch - as one who saw this with his own eyes - to something few could. (Despite how incredibly realistic my post was the other day, I truly didn't get to go. It was only James, John and Peter. Not Susanne.)
John 1 says,
14The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the One and Only, who came from the Father, full of grace and truth.
And John's gospel emphasizes "the deity of Christ and the glory of his person."
Peter also speaks of this event on the mountain.
16We did not follow cleverly invented stories when we told you about the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty. 17For he received honor and glory from God the Father when the voice came to him from the Majestic Glory, saying, "This is my Son, whom I love; with him I am well pleased." 18We ourselves heard this voice that came from heaven when we were with him on the sacred mountain. (II Peter 1)
Next in this chapter we see a man bringing his demon-possessed son to Jesus. Apparently he'd ask the disciples to heal his boy with no luck! Were these the 9 disciples not chosen to go up the mountain with Jesus? In his commentary, Warren Wiersbe speculates that maybe these guys were a bit disgruntled that they were left behind. Therefore they slacked off on their prayer and their faith weakened. Then when this father asked for them to heal his son, they tried not realizing their power had left them. Kind of like Samson who didn't realize his supernatural strength was gone until the Philistines were able to bind him and he was - for the first time in his life - unable to break what kept him in bondage.
Jesus heals the boy and when his disciples ask why they were not able to perform this miracle, Jesus said it was their lack of faith! Then Jesus said if we have faith the size of a mustard seed, nothing would be impossible for us. Wiersbe points out that using a mustard seed as an example shows two things. First God can use a small amount of faith, but at the same time a seed is living and growing. Thus our faith - though it may start out small - is alive and it's growing bigger and bigger as we experience the faithfulness of God. After all, He is the power behind our faith! With faith the disciples could have healed this suffering son because the power behind the faith was from above.
I read a book recently and the main character mentioned how at times of suffering she would often forget God's faithfulness in the past. But remembering His goodness and the way He has helped us is often what keeps us going when troubles in life seem to overwhelm us. So whatever struggles you are going through, take heart. As the old song goes, "count your many blessings, see what God has done." I suspect as you start remembering the faithfulness of God, your heart will be cheered ... even if it's only a bit, like maybe the size of a mustard seed.
Hey, God can work with that! :)