In chapter fourteen of Indwelling Sin in Believers, John Owen said he was now ready to examine how the power of Sin is demonstrated by the effects it has in the lives of believers. There are two kinds of effects. First is the great actual flare-ups of sin in their lives. Secondly, there is the habitual decline from the state and condition of obedience and communion with God, “which they had obtained.” Both originate with the law of sin, and both are convincing evidence of its power and efficacy.

First, Owen considers the eruptions of actual sin in the lives of believers, that are recorded in Scripture. The examples Owen gives are not of the ordinary sort of believers, but men with a distinct reputation, “on account of their walking with God.” Noah, Lot, David, Hezekiah, among others. An ordinary method could not have turned them. “It was a poison that no athletic constitution of spiritual health, no antidote could withstand,” namely indwelling sin.

These men did not fall into their great sins at the beginning of their profession of faith. “But after a long course of walking with God, and acquaintance with all these things.”

Who can look to have a greater stock of inherent grace than those men had? To have more experience of God and the excellency of his ways, the sweetness of his love. And of communion with him than they had? Who has either better furniture to oppose sin withal, or more obligations so to do than they? And yet we see how fearfully they were prevailed against.

Are we more holy, wise, and watchful than David, of whom it was said, that he was “a man after God’s own heart?” Or, are we better than Hezekiah, who appealed to God himself, that he had served him “with a whole heart?” (2 Kings 20:3) These men are metaphorically given as buoys to us. That we may discover the sands, the shelves, the rocks “whereupon they made their shipwreck.” And it would have been to their ruin, “had not God been pleased, in his faithfulness, graciously to prevent it.”

Then Owen turned to the habitual decline from zeal and holiness that they had obtained; a state and condition “which are found in many believers.” It often falls out, that instead of manifesting the promises of spiritual growth and improvement, decay and decline are found in many of the saints of God. This is principally from the strength and efficacy of indwelling sin. Owen then observed how some of the saints so decline “from that growth and improvement in faith, grace, and holiness, which might justly be expected from them.”

One example he gave was of men who seem to retain a good zeal for truth. Although they make a good outward appearance, they are found “to be the most abominable.” They cry out against errors, but not for the sake of truth. They do so to support their views and interests. “Let a man be on their party, and promote their interest, be he ever so corrupt in his judgment, he is embraced and it may be, admired.” Notice how Owen’s words apply equally to our time:

This is not zeal for God, but for a man’s self. It is not “the zeal of thing house hath eaten me up;” but “Master, forbid them, because they follow not us.” Better it were, doubtless, for men never to pretend to any zeal at all, than to substitute such wrathful selfishness in the room of it. . .

We need then go no further than this wretched generation wherein we live, to evince the truth of the observation laid down, as the foundation of the instance insisted on. The Lord give repentance before it is too late.

James’ epistle noted the general rule, “that lust, or indwelling sin is the cause of all actual sin, and all declensions in believers.” In the covenant of grace there is abundant provision made, not only for preventing decline and decay in believers, “but also for their continual carrying on towards perfection. The word of the gospel and its ordinances, are given to us for this end (Ephesians 4:11-15). They were all given in order to prevent the decay and decline in the saints, “for building up the body of Christ.” They were designed for our safe-guarding and deliverance from all their attempts and assaults.

So that we no longer live as children, tossed to and fro, carried by craftiness and human into deceitful schemes. “Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ” (Ephesians 4:15). This is the purpose of all gospel ordinances, “namely to preserve believers from all decays of faith and obedience, and to carry them on still towards perfection.” These are the means by which God causes the vine to grow and produce fruit.

We see people living under and enjoying all the means of spiritual thriving, yet they wither and waste away instead of becoming fat and flourishing. This argues there is some secret powerful distemper, whose noxious qualities hinder the virtue and efficacy of the means they enjoy. “This is indwelling sin.” In the midst of all the precious means of growth and flourishing, it can bring leanness on the souls of men.

It may well make us tremble, to see men living under, and in the use of the means of the gospel, preaching, praying, administration of sacraments, and yet grow colder every day than other, in zeal for God; more selfish and worldly, even habitually to decline, as to the degrees of holiness which they had attained to.

In addition to these means of spiritual growth and improvement, there are also the supplies of grace continually provided to the saints from Christ Jesus, who communicates spiritual life to all who are his. He gives out sufficiently to afford them a strong, vigorous, thriving, flourishing life. He comes not only to provide life to his sheep, but he came to give it abundantly (John 10:10), “so that they may be fat and fruitful.” So it is with every member of the whole body of Christ. “The end of all communications of grace, and supplies of life from this living head. Is the increase of the whole body, and every member of it.”

The withering and decay of any member of Christ’s mystical body is not a result of his failure to communicate grace for an abundant life. Rather, it is from the powerful intervention and opposition of indwelling sin. Where lust grows strong, a great deal of grace will be spent just to keep the person alive. It spends its strength and power in withstanding the continual assaults of violent corruptions and lusts, “so that it cannot put forth its proper virtue towards further fruitfulness.”

This is clear evidence of the efficacy of indwelling sin. Namely, that it is able to prevent and check the mighty power of grace. “This makes so many trees barren in fertile fields.” It compels the fruitful vineyard to bring forth so many wild grapes. So great is the power and efficacy of indwelling sin, that it often leads saints to decline in their walk with God, as with Samson.

Such is this indwelling sin, if not watched over; it breaks all the cords made to bind it; it blunts the instruments appointed to root it up; it resists the instruments appointed to root it up; it resists all healing medicines, though ever so sovereign; and is therefore, assuredly of exceeding efficacy.

The end result of recognizing this power of sin is that we must be careful to avoid and prevent its scheming. Of all the effects it produces, there is none more dangerous than how it habitually weakens many believers from their former ways and attainments, notwithstanding all the sweetness their souls have found in them.