If God's Word be true and men are dead in their sins and haters of God then it is only by faith in the power of God's choosing, Christ's dying, and the Spirit's moving that we preach to sinners. How else can the dead be made alive? How else can foe become friend? How else can a rebel become a son? Do our words have power? Do we? Does such a thing happen from mere realization and motivation? No! Such a thing is a miracle! A miracle only possible by the Creator of all, the Sustainer of all, the Lord of all.
Shed off speeches of motivation and lectures of morality. Cling only to Christ and His Gospel. Preach only Christ crucified. Trust only God.