To return when the Spirit makes intercession in thee or helps thee to make intercession with groans which cannot be uttered, let these groans be against sin rather than for divine comforts; groan rather for redemption from sin than from any other misery.
Watchfulness is of singular use to such as would be successful in this business of mortification. You must fight with sin ere ye can mortify it, for sin is not so tame as to make no resistance.