The Transfiguration is one of the the significant events in the gospel narratives about Jesus. The other significant events are Baptism, Crucifixion, Resurrection and Ascension.
Like the other significant events, it is about Jesus and it reveals His identity as well as His mission.
Certainly there is no speculation about the voice from heaven and its content - "This is my Son, the Beloved. Listen to him."
And the setting on the mountain with the appearance of the Moses and Elijah point to the meaning of the event.
And that is, in Jesus, the Law and the prophesies of the Old Testament has been fulfilled.
Also in Jesus, divinity has dwelt among humanity, and in Jesus is the connecting point and the bridge between heaven and earth.
So for those who believe in who Jesus is, there can be no other alternative options in life to follow.
As St. Peter would say in the 2nd reading, his faith in Jesus is not any cleverly invented myth, otherwise everything will fall apart sooner or later.
And for us who profess our faith in Jesus, then He will be the lamp lighting our way through the dark until the dawn comes and the morning star rises in our minds.
Yes, we have to listen to Him as the voice of the Father has commanded us to do.
When we listen, and truly believe, we too will change and be "transfigured" like Jesus.