Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof.

Let not then the sin reign in your mortal body, to obey it in its desires;

Let not Sin therefore reign as king in your mortal bodies, causing you to be in subjection to their cravings;

For this cause do not let sin be ruling in your body which is under the power of death, so that you give way to its desires;

Therefore do not let sin reign in your mortal bodies and compel you to obey its cravings.

Ne ergo regnet peccatum in mortali vestro corpore, ut illi obediatis in cupiditatibus suis:

Let not sin then, etc. He now begins with exhortation, which naturally arises from the doctrine which he had delivered respecting our fellowship with Christ. Though sin dwells in us, it is inconsistent that it should be so vigorous as to exercise its reigning power; for the power of sanctification ought to be superior to it, so that our life may testify that we are really the members of Christ. I have already reminded you that the word body is not to be taken for flesh, and skin, and bones, but, so to speak, for the whole of what man is. [1] This may undoubtedly be inferred from the passage; for the other clause, which he immediately subjoins respecting the members of the body, includes the soul also: and thus in a disparaging manner does Paul designate earthly man, for owing to the corruption of our nature we aspire to nothing worthy of our original. So also does God say in Genesis 6:3; where he complains that man was become flesh like the brute animals, and thus allows him nothing but what is earthly. To the same purpose is the declaration of Christ, "What is born of the flesh is flesh." (John 3:6.) But if any makes this objection -- that the case with the soul is different; to this the ready answer is -- that in our present degenerate state our souls are fixed to the earth, and so enslaved to our bodies, that they have fallen from their own superiority. In a word, the nature of man is said to be corporeal, because he is destitute of celestial grace, and is only a sort of empty shadow or image. We may add, that the body, by way of contempt, is said by Paul to be mortal, and this to teach us, that the whole nature of man tends to death and ruin. Still further, he gives the name of sin to the original depravity which dwells in our hearts, and which leads us to sin, and from which indeed all evil deeds and abominations stream forth. In the middle, between sin and us, he places lusts, as the former has the office of a king, while lusts are its edicts and commands.

Footnotes

1 - That is, as a corrupt being: literally it is "for the whole mass of man." The "body" here may be the same with that of "the old man" in Romans 6:6; and the word for "lusts," epithumiais, is often applied to designate the desires of the mind as well as the lusts of the natural body. The word, thneto, "mortal," would in this case mean, doomed to die, having been crucified; it is a body in the process of dying. Innate sin is here personified as a king, a ruler, and as having a body, he being "the old man;" and this body is represented as belonging to Christians -- "your," as the old man is -- "our old man." -- Ed.

Let not sin therefore - This is a conclusion drawn from the previous train of reasoning. The result of all these considerations is, that sin should not be suffered to reign in us.
Reign - Have dominion; obtain the ascendency, or rule.
In your mortal body - In you. The apostle uses the word "mortal" here, perhaps, for these reasons,
(1) To remind them of the tendency of the flesh to sin and corruption, as equivalent to "fleshly," since the flesh is often used to denote evil passions and desires (compare Romans 7:5, Romans 7:23; Romans 8:3, Romans 8:6); and,
(2) To remind them of their weakness, as the body was mortal, was soon to decay, and was therefore liable to be overcome by temptation. Perhaps, also, he had his eye on the folly of suffering the "mortal body" to overcome the immortal mind, and to bring it into subjection to sin and corruption.
That ye should obey it - That sin should get such an ascendency as to rule entirely over you, and make you the slave.
In the lusts thereof - In its desires, or propensities.

Let not sin therefore reign - This is a prosopopoeia, or personification. Sin is represented as a king, ruler, or tyrant, who has the desires of the mind and the members of the body under his control so that by influencing the passions he governs the body. Do not let sin reign, do not let him work; that is, let him have no place, no being in your souls; because, wherever he is he governs, less or more: and indeed sin is not sin without this. How is sin known? By evil influences in the mind, and evil acts in the life. But do not these influences and these acts prove his dominion? Certainly, the very existence of an evil thought to which passion or appetite attaches itself, is a proof that there sin has dominion; for without dominion such passions could not be excited. Wherever sin is felt, there sin has dominion; for sin is sin only as it works in action or passion against God. Sin cannot be a quiescent thing: if it do not work it does not exist.
That ye should obey it in the lusts thereof - Αυτῃ εν ταις επιθυμιαις αυτου. This clause is wanting in the most ancient and reputable MSS. and in the principal versions. Griesbach has left it out of his text; and Professor White says, Certissime delenda: "These words should certainly he expunged" they are not necessary to the apostle's argument; it was enough to say, Let not sin reign in your mortal bodies, that ye should obey it. If it be there it will reign there; and its reign supposes, necessarily, the subjection of that in which it reigns. A king reigns when his laws are enforced, and the people obey them. When there is no executive government there is no reign. There may be a royal shadow there, but there is no king.

(6) Let not sin therefore (o) reign in your mortal body, that ye should obey it in the lusts thereof.
(6) An exhortation to contend and strive with corruption and all the effects of it.
(o) By reigning Paul means that principal and high rule which no man strives against, and even if anyone does, it is in vain.

Let not sin therefore reign in your mortal body,.... Since grace reigns in you, sin should not: seeing ye are dead to sin, are baptized into the death of Christ, and are dead with him, and alive through him, sin therefore should not reign in you, and over you. This exhortation does not suppose a freewill power in man naturally, for this is spoken to persons, who had the Spirit and grace of Christ, and in whom God had wrought both to will and to do of his good pleasure; nor is this exhortation unnecessary to believers, though they are dead to sin, and though God has promised it shall not have the dominion over them, and though reigning sin, as divines say, cannot be in regenerate persons; for though they are entirely dead to sin as justified persons, yet not perfectly so as sanctified: they are indeed dead to sin, but sin is not dead in them; it struggles, it makes war, leads captive, and threatens absolute and universal dominion, wherefore such an exhortation is necessary; besides, though God has promised that sin shall not have the dominion, yet making use of means, such as prayer to God that it may not, striving against it, opposing it, in order to hinder its dominion, are no ways inconsistent with the promise of God, whose promises often have their accomplishment in the use of means: moreover, whereas some divines say, that reigning sin may be and others that it cannot be in regenerate persons, it should be observed, that if by reigning sin is meant, sinning against God out of malice and contempt, with the whole heart, without any struggle against it, or repentance for it, or so as to lose the grace of God, and never rise more, then it must be said that it cannot be in a regenerate man; but if by it is meant, falling into sin against their consciences, knowingly and willingly, so as to distress their minds, lose their peace, and grieve the Spirit of God, so as to be held under it, and be led captive by it, such power sin may have in them, and over them; and therefore the exhortation is not needless; and when the apostle says, let it not reign "in your mortal body", by it is either meant the whole man, or rather the body only, which is the instrument of sinning, and is become mortal through sin; and being so, is a reason why it should not reign in it, since it has done so much mischief to it already: and this also denotes the time of sin's being in us, and of the danger of its reigning in us; it is only whilst we are in this mortal body; and the consideration of our mortality should quicken us to war against sin, and be careful not to
obey it in the lusts thereof; the lusts of the body, or flesh, which are therefore sometimes called fleshly lusts, are many, and have great power and influence; and may be said to be obeyed, when provision is made to fulfil them, when these are the business of a man's life, and the whole of his conversation is taken up in them, without struggle against them, or opposition to them; and heroin lies the reign of sin.

WHAT PRACTICAL USE BELIEVERS SHOULD MAKE OF THEIR DEATH TO SIN AND LIFE TO GOD THROUGH UNION TO THE CRUCIFIED SAVIOUR. (Romans 6:12-23)
Let not sin therefore--as a Master
reign--(The reader will observe that wherever in this section the words "Sin," "Obedience," "Righteousness," "Uncleanness," "Iniquity," are figuratively used, to represent a Master, they are here printed in capitals, to make this manifest to the eye, and so save explanation).
in your mortal body, that ye should obey it--sin.
in the lusts thereof--"the lusts of the body," as the Greek makes evident. (The other reading, perhaps the true one, "that ye should obey the lusts thereof," comes to the same thing). The "body" is here viewed as the instrument by which all the sins of the heart become facts of the outward life, and as itself the seat of the lower appetites; and it is called "our mortal body," probably to remind us how unsuitable is this reign of sin in those who are "alive from the dead." But the reign here meant is the unchecked dominion of sin within us. Its outward acts are next referred to.

Let not sin reign even in your mortal body - It must be subject to death, but it need not be subject to sin.