Today is the feast day of the Transfiguration of Our Lord.
The Transfiguration of Christ is when Jesus becomes transfigured (experiences a moment of divine radiance), the voice of God identifies Jesus as his beloved son, his disciples fell to the ground afraid of what they saw/heard, and Jesus tells them not to be afraid.
Collect of the Day: O God, who on the holy mount didst reveal to chosen witnesses thy well-beloved Son wonderfully transfigured: Mercifully grant-unto us such a vision of his divine majesty, that we, being purified and strengthened by thy grace, may be transformed into his likeness from glory to glory; through the same thy Son Jesus Christ our Lord. Amen.