"utterly silent, or says that nothing of this nature is committed unto it of God: nay, the strength it hath it gives unto sin for the condemnation of the sinner: 'The strength of sin is the law.'"
... Sin will never be dethroned by it; it will not give place unto the law, neither in its title nor its power.
In other words, when confronted with temptation or sin's remaining power in our lives, it's a fool's errand to look to the law for help. When in direct conflict with sin, the law is powerless to help us. When we look to the law for help against sin, the law just points right back at us, in turn exposing our complete lack of inward righteousness and inherent weakness in that battle. Yet, as is the case today, there were some in Owen's day who were advocating that after justification, which is received through faith alone, we should then to look primarily to the law for our sanctification in order to fight sin and produce works of righteousness - the old "in by grace, complete by works"salvation formula. Owen continues:
It is otherwise with them that are “under grace.” Sin shall not have dominion over them; strength shall be administered unto them to dethrone it.
“Grace” is a word of various acceptations in the Scripture. As we are here said to be under it, and as it is opposed unto the law, it is used or taken for the gospel, as it is the instrument of God for the communication of himself and his grace by Jesus Christ unto those that do believe, with that state of acceptation with himself which they are brought into thereby, (Rom. v. 1, 2). Wherefore, to be “under grace” is to have an interest in the gospel covenant and state, with a right unto all the privileges and benefits thereof, to be brought under the administration of grace by Jesus Christ, — to be a true believer...
1. Is it that there shall be no sin in them any more? Even this is true in some sense. Sin as unto its condemning power hath no place in this state, (Rom. viii. 1). All the sins of them that believe are expiated or done away, as to the guilt of them, in the blood of Christ, (Heb. i. 3, 1 John i. 7). This branch of the dominion of sin, which consists in its condemning power, is utterly cast out of this state. But sin as unto its being and operation doth still continue in believers whilst they are in this world; they are all sensible of it. Those who deceive themselves with a contrary apprehension are most of all under the power of it, (1 John i. 8). Wherefore, to be freed from the dominion of sin is not to be freed absolutely from all sin, so as that it should in no sense abide in us any more. This is not to be under grace, but to be in glory.
2. Is it that sin, though it abides, yet it shall not fight or contend for dominion in us? That this is otherwise we have before declared. Scripture and the universal experience of all that believe do testify the contrary; so doth the assurance here given us that it shall not obtain that dominion: for if it did not contend for it, there could be no grace in this promise, — there is none in deliverance from that whereof we are in no danger.
But the assurance here given is built on other considerations; whereof the first is, that the gospel is the means ordained and instrument used by God for the communication of spiritual strength unto them that believe, for the dethroning of sin. It is the “power of God unto salvation,” (Rom. i. 16), that whereby and wherein he puts forth his power unto that end. And sin must be really dethroned by the powerful acting of grace in us, and that in a way of duty in ourselves. We are absolved, quitted, freed from the rule of sin, as unto its pretended right and title, by the promise of the gospel; for thereby are we freed and discharged from the rule of the law, wherein all the title of sin unto dominion is founded, for “the strength of sin is the law:” but we are freed from it, as unto its internal power and exercise of its dominion, by internal spiritual grace and strength in its due exercise. Now, this is communicated by the gospel; it gives life and power, with such continual supplies of grace as are able to dethrone sin, and forever to prohibit its return...
... This is one principal difference between the law and the gospel, and was ever so esteemed in the church of God, until all communication of efficacious grace began to be called in question: The law guides, directs, commands, all things that are against the interest and rule of sin. It judgeth and condemneth both the things that promote it and the persons that do them; it frightens and terrifies the consciences of those who are under its dominion. But if you shall say unto it, “What then shall we do? this tyrant, this enemy, is too hard for us. What aid and assistance against it will you afford unto us? what power will you communicate unto its destruction?” Here the law is utterly silent, or says that nothing of this nature is committed unto it of God; nay, the strength it hath it gives unto sin for the condemnation of the sinner: “The strength of sin is the law.”
But the gospel, or the grace of it, is the means and instrument of God for the communication of internal spiritual strength unto believers. By it do they receive supplies of the Spirit or aids of grace for the subduing of sin and the destruction of its dominion. By it they may say they can do all things, through Him that enables them. Hereon then depends, in the first place, the assurance of the apostle’s assertion, that “sin shall not have dominion over us,” because we are “under grace.” We are in such a state as wherein we have supplies in readiness to defeat all the attempts of sin for rule and dominion in us.All quotes are from A Treatise of the the Dominion of Sin and Grace.