Romans 6:12

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.