“If so, is it as my Thessalonians quote says, that it’s God’s word not the words of men”?
The question would be: how did the Apostle Paul know that the Old Testament was the Word of God?
Also, this verse would show the validity of oral tradition because Paul preaching Christ (the New Testament was not completed at this time) and establishing church polity.
“I realize that it wouldn’t make sense (unless you were a believer) to do it that way before I said it. However since it speaks for itself and is God’s word, with no errors, I’ll quote it for everything. “
You are missing the point: how do you know it is God’s Word? Someone may write a book without errors, but that does not make it the Word of God.
Another question would be: how would you know what books to choose to include in the Bible, say when the New Testament canon was formed?