Charles Koller’s next appeal that he finds in scripture is the appeal to fear. Koller notes that this appeal has been greatly neglected. I would concur and say that among many it is no longer heard at all. No one wants to hear or preach about the “wrath of God” or about “judgment,” but we cannot preach the whole counsel of God without at least referring to this.
God uses this appeal in the scriptures for example, in Acts 9:4,6 we see God knocking Saul down turning him into Paul. The prophets used this appeal for example when Nathan said in 2 Samuele 12:7, “Thou art the Man!” The fear of judgment helped Nineveh to repent (Jonah 3:4).
Certainly fear is not the best incentive to come to right, but when all else fails, it might be something to help some take steps in the right direction.