Do not believe that your convictions are too deep and too strong ever to leave you. They are perhaps not stronger than those of Felix when he trembled, of Herod when he heard John and did many things gladly, of Ahab when he humbled himself, or of king Saul when he lifted up his voice and wept. Conviction of itself, is not a saving grace. It is itself no pledge of salvation. It may leave one midway between carelessness and conversion, just as Lot’s wife was left between Sodom and Zoar. If your convictions do not lead to Christ, and that speedily, you may become familiar with them, and their effect be lost up on you. Conviction of itself, is not conversion. Conviction can save no man. Misconceive not the terms of salvation. On this point there is much danger. Be specially guarded that you do not attempt to substitute your own distress of mind for the sufferings of Christ. Sin is neither pardoned nor expelled, by the anguish of any sinful worm. The more distressed men are, the stouter is the rebellion of your sins. Your own sufferings, in this world or the next, cannot save you. No tears, no blood, no cross, no death, no intercession but those of Christ can avail for any! Never lose sight of the blessed truth, that salvation is wholly by grace, through faith in Christ Jesus.
William S. Plumer, Vital Godliness: A Treatise on Experimental and Practical Piety – Chapter 7 – Cases of Religious Distress