"For we have not followed cunningly devised fables, when we made known unto you the power and coming of our Lord Jesus Christ, but were eyewitnesses of his majesty. For he received from God the Father honour and glory, when there came such a voice to him from the excellent glory, 'This is my beloved Son, in whom I am well pleased.' And this voice which came from heaven we heard, when we were with him in the holy mount. We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Spirit." 2 Pet 1:16-21
Peter was an 'eyewitness of His Majesty' were He was there on the mountain hearing the Father speak about the Son. We are 'witnesses' when we hear the scriptures. The Spirit speaks within our range of hearing just like the Father spoke about the Son and the disciples heard it.
Private interpretation gets the scripture to sound the way man wants it to sound. What the scripture really says is "This is my beloved Son: hear him." (Mark 9:7; Luke 9:35). It is a merciful correction to our viewpoint and we do well to hear it.
This is the light that shines in a dark place.
If we hear the words this way... as being focused on and through the uniquely approved Son then we hear them unfiltered. They are a voice not just a book. Truth is a person speaking.
If we really hear God's voice we become manifestations of His voice.
"And suddenly, when they had looked round about, they saw no man any more, save Jesus only with themselves. And as they came down from the mountain, he charged them that they should tell no man what things they had seen, till the Son of man were risen from the dead. And they kept that saying with themselves, questioning one with another what the rising from the dead should mean." Mark 9:8-10
Once corrected we find that all we see is Jesus. We walk down hill with Him. Our weigh is different as we descend from the mountain back into practical life. We carry a secret. The downhill trek is so much easier than the one uphill ever was.