When Peter saw the awesomeness of Christ's transfiguration, he had an all too human feeling, and said, "Lord, it is good for us to be here, if You wish, let us make here three tents here" (Matthew 17:4).
He was full of joy and amazement, but the first thing he thought about was preserving this joy, not sharing it, not running to others and telling them about it.
We also have this great joy, that is our Christian faith, and we also, like Peter, tend to preserve it and hide it, rather than bring it to our family members, neighbors and everyone around us.
Christ's Gospel has been preached on all continents of the earth, but we are seeing a reverse process now - people (Christians or not) are just as likely to have never heard of the Gospel, as they are to have heard about it. Let alone have any idea what it actually says.
As they were coming down from Tabor, Christ told Peter, John, and James to not tell anyone about what they saw until after "the Son of Man is risen from the dead" (Matthew 17:9). We, as the successors of the apostles, live precisely in the time "after the Son of Man is risen from the dead."
We have this great opportunity to "make disciples of all nations" (Matthew 28:27), to baptize, teach and preach the Gospel of Christ.
May Christ's everlasting Light also shine upon us to give us courage and strength to be worthy disciples of Christ.
Joyous Feast of Transfiguration!