The Transfiguration of Christ

12th-century icon of the Transfiguration

The Feast of the Transfiguration, on August 6th, commemorates what many consider to be the highest point of Jesus' earthly life, when he was "transfigured" by a brilliant white light at the top of a mountain and proclaimed to be the well-loved Son of God from a heavenly voice.

According to the Gospels of Luke (9:28-36), Mark (9:1-8), and Matthew (17:1-6), the Transfiguration occurred when Jesus travelled to the top of a mountain to pray with three of the Apostles, Peter, John, and James. Upon reaching the summit, Jesus was transfigured, his entire body being filled with a shining white light, as though his person were filled with clear fire. 

Moments later, the prophets Elijah and Moses appeared to either side of Jesus, and began to speak with him of his burden and impending death. Then, a blazing cloud appeared overhead, and a voice spoke from heaven (typically taken to be God), saying that Jesus was his beloved son, in whom he was well pleased. After the event was over, Jesus asked the three Apostles to keep the occurrence a secret until the Son of Man rose from the dead. 

Interpretations of the Transfiguration
Generally speaking, the primary significance of the Transfiguration exists in the light which shines from Jesus' body on the mountaintop, which is typically held to be a sign of his internal divinity fully manifesting itself in the material world. It is also the second of time that he is called a beloved son by a heavenly voice, the first being when he is baptized by John. As a result of these events, the Transfiguration is considered the turning point between Jesus' prophetic ministry and priestly (or divine) ministry