That is a total misunderstanding of scripture. In II Peter 1:20 Peter is stating that scripture does not come from man, but from God. Check the entire context, especially vs 21.
20 Understanding this first, that no prophecy of scripture is made by private interpretation.
21 For prophecy came not by the will of man at any time: but the holy men of God spoke, inspired by the Holy Ghost.(2 Peter 1)
Indeed the scripture has its origin in God, but it is given us by inspired "holy men". We are not to interpret it privately. Plain language, folks.