God used Paul as an instrument to write down a portion of His Word.
What Paul wrote was 100% inspired by God, except in one or two instances where he asked permission to write down his own thoughts. What God wrote via Paul is only out of whack with the rest in false translations - deliberately created by the enemy to take away from what God explicitly stated. A truthful translation forms an unbreakable chain of evidence.
The whole Word of God was inspired by God, not just portions of it. This is why it is called the Word of God and not the Word of Paul, etc.
Understand that all of those who helped to create God's Word were mere instruments in God's Hand - it doesn't contain their own words and ideas (except in instances where permission was asked to state their own words and ideas).