The fall of man into sin has changed his nature in a profound way. Sin is not simply a habit he can break out of by resolutions, or a matter of correction to his external behaviour, or of learning a few manners; it is deeply embedded in the warp and woof of his being.
What can cure us of our folly? Only the gospel! Only the work of the Spirit of God in our hearts can bring us under conviction, for the Spirit alone is skilful enough to catch us in our twisting and turning away from truth, and hedge us in at every turn until we confess our wickedness to God. Only he can bring the sinner to the point where he shuts his mouth and stops offering any excuse for his sin. Only the Spirit can bring us to humble ourselves before God and come to Jesus Christ for salvation, and admit that we cannot save ourselves. Only the Spirit can create a new nature in us which does not contain that foolishness which pervades the entirety of our fallen nature. Let God’s people not use any lesser cure than the gospel itself, preached to a lost world. Let them abandon all gimmicks such as drama and music and carnal attraction to try to bring people to Christ. All these things will fail, for it may seem that the sinner has yielded to Christ, but the change falls short of true conversion. Foolishness has not been driven out, and is still in charge of the heart. A minor adjustment is all that has taken place, but there has been no new birth.