Sin may be dormant or restrained but remains dangerous and deceptive within.
"It is true that natural corruption doth not break out in all with a like violence; but a benumbed snake is a snake; a sow washed is not changed. As when the liver groweth, other parts languish, so great lust intercepteth the nourishment of other corruptions." It seems, then, that there may be a winter to our corruptions as well as to animal and vegetable life, and then the sin which dwelleth in us may be quiet, as though frozen into a rigid powerlessness: but what of that? The weather will change, and then the nest of vipers will be all astir again, each one with venomed tooth aiming to destroy. Experience has also taught the wise observer that sin may be bound by sin, and one ruling passion may hold the rest in check. One man is kept from licentiousness by covetousness: he would be glad to revel in vice if it were not so expensive; another would be a rake and a spendthrift, but then it would not be respectable, and thus his pride checks his passions. This restraint of sin by sin is no proof that the nature is one jot the better, but that it puts on a fairer appearance, and is more likely to deceive. When Satan casts out Satan it is a deep game; but we must not be deceived by the diabolical trick. When the devil's work seems good it is at its worst.
Nothing will answer with inbred sin but the killing of it. When Joshua had the five kings in the cave at Makkedah, he was not content to shut them in with great stones. No, he took special pains to fetch them out, and hang them up. The condemned race must die, and then Israel can breathe freely. Sin will be our death if we do not put it to death. Checks and restraints are of small value; what is needed is the root-and-branch cure—crucifixion with Christ. To cure sin by sin is a mere piece of stage-playing, which will never answer before God. We need to be purged of the cause of sin, yea, of all sin, or we can never enter heaven. O thou destroyer of the serpent and his seed, break the head of sin within me, so that it may never lift up its usurped power within my soul. Let the sword of the Spirit do a thorough work within my nature, till not a single rebel lust shall remain alive in the wide domains of my being. Furbish thy sword, O Captain of the Host, and do thine office within me, for I cannot rest till sin is slain.