How do we know the doctrine of the Transfiguration is true?

The truth of the Transfiguration is supported not only by Mark’s account but also echoed in the Gospel accounts of Matthew and Luke, each describing this stunning display of Jesus' divine nature. The significance is further emphasized through the confirmation of Peter in his second epistle, where he declares that they did not follow cleverly devised myths but were eyewitnesses of His majesty (2 Peter 1:16). This collective testimony acts as a strong foundation for the doctrine, underscoring that Jesus is indeed the Son of God, whose glory was momentarily unveiled for the sake of His closest disciples.