Do not trust yourself to your own opinions, but take them to Christ and see whether they are in conformity with the faith (Rom. 12:7) and the Word of the holy Gospel. I, too, occasionally have beautiful and splendid thoughts, and I believe that the Holy Spirit inspired them. But when I judge them in the light of faith, I realize that they are sheer filth, sinful and impure.

—Martin Luther, Luther’s Works, Vol. 22: Sermons on the Gospel of St. John Chapters 1—4, 272.