Because we walk by faith and not after what the eyes see the temporal we can understand the two witnesses of God that make one witness . is the law and prophets likened by Moses the law giver and Elias the unseen power of the law of faith . Not Enoch and Alias.
Moses represent the letter of the law "death" It will not enter the promise land again typified by Moses. . The word of God the gospel will be silenced or killed for a short while, no new faith during that period. .
The vison that worked in the mind of Peter was not mixed with faith Peter took it as literal . The father introduce the son surrounded by the two witnesses of His word . The law and the prophets . Hear ye Him who dwells in us. not to the flesh as did Peter who denied the faith again and again
Matthew 17:3-5 King James Version (KJV) And, behold, there appeared unto them Moses and Elias talking with him. Then answered Peter, and said unto Jesus, Lord, it is good for us to be here: if thou wilt, let us make here three tabernacles; one for thee, and one for Moses, and one for Elias. While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him.
Luke 16:15-17 King James Version (KJV) And he said unto them, Ye are they which justify yourselves before men; but God knoweth your hearts: for that which is highly esteemed among men is abomination in the sight of God. The law and the prophets were until John: since that time the kingdom of God is preached, and every man presseth into it. And it is easier for heaven and earth to pass, than one tittle of the law to fail.