“Knowing this first, that no prophecy of Scripture is of any private interpretation, for prophecy never came by the will of man, but holy men of God spoke as they were moved by the Holy Spirit”
(2 Peter 1:20-21 NKJV)

God Himself originated Scripture

These verses are widely misused and misunderstood.  Some assume that Peter is giving approval to his readers to interpret Scripture as it pleases them.  They insist on the flexibility of Old Testament prophesies, allowing the reader to use Scripture to prove just about anything.  Catholics believe the passage forbids conclusions that are not endorsed by their “clergy.”  These ideas are false and foreign to the context.   

1. Peter has shown that the life, the work, and the evidence of Jesus makes the prophetic word even more certain (v.19).  Placing the prophecies beside His life and actions proves beyond any doubt that Jesus is the Messiah.  His transfiguration alone proves that He is God’s Son (Mt.17:1-5).  The presence of eyewitnesses at His transfiguration (Peter, James, and John, v.16; Mt.17:1-5) shows that these things really happened. These powerful evidences, in addition to His resurrection, puts the word of prophecy beyond dispute.  
2. Whatever Peter is saying in v.21, he does not deny in v.20.  ‘Private interpretation’ refers to the prophets who wrote Scripture, not to the interpretation that readers might force upon the prophecy. False prophets wrongly interpreted prophecies (2 Peter 2:1); true prophets did not.  Though Isaiah did not always understand some of his own prophecies (see 1 Peter 1:10-12) he nevertheless received his revelation from God.  So, we could express Peter’s affirmation in verse 20, “No prophecy of Scripture is of any private origination.”   Its origin is of God, not of man.   
3. Note that verse 21 begins with “for.”  Verse 21 explains verse 20 – prophecy never came by the will of man (men did not originate Old Testament prophecies).  Prophets of God were moved by the Holy Spirit.  God Himself originated Scripture.

This passage affirms the same truth as 2 Timothy 3: “All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work” (verses 16-17).  What does this mean to me?  On the mount of transfiguration, the great voice of God commanded the disciples, “This is My beloved Son, in whom I am well pleased.  Hear Him!”  Dare we do any less? 

– Rick Duggin