There are verses in the New Testament where Paul says that he is speaking, not the Lord. How does this affect the doctrine of inspiration which states that every word in the Bible is true and from God? Let's take a look at these three verses.
- 1 Cor. 7:12, "But to the rest I say, not the Lord, that if any brother has a wife who is an unbeliever, and she consents to live with him, let him not send her away."
- 1 Cor. 7:25, "Now concerning virgins I have no command of the Lord, but I give an opinion as one who by the mercy of the Lord is trustworthy."
- 2 Cor. 11:17, "That which I am speaking, I am not speaking as the Lord would, but as in foolishness, in this confidence of boasting."
First of all, we need to understand what inspiration means. 2 Tim. 3:16 says, "All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness." The word "inspired" is θεόπνευστος theopneustos. It means God-breathed.
The inspiration of the Bible does not mean that every single word in the Bible is dictated by God or is from God. Instead, it means that whenever the Bible speaks in regards to history, truth, God, morality, etc., it is without error. In addition, within all of this, it will accurately record the sinful behavior of people, such as their lies. It doesn't mean that those lies were inspired from God.
Take Genesis 3 where the devil says to Eve, "You surely shall not die!" (Gen. 3:4). The words are not "God breathed." But, the words are accurately recorded within the "God breathed" scriptures. This is what happened, and in the inspired word of God we can trust that the words are accurately represented and it is up to us to learn from what is recorded there.
Back to Paul's statements.
In the verses where Paul said that he was speaking, not God, then it is absolutely true and correct that he was speaking and not God. But, this also means that he knew when he was speaking for God. This is no challenge to the inspiration of the word of God at all. Paul was able to distinguish between his own words and those of the Lord and, again, the Bible accurately records what was said -- including the differentiation between what was Paul's opinion and what was God's word.