I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.
I exhort you — St. Paul uses to suit his exhortations to the doctrines he has been delivering. So here the general use from the whole is contained in the first and second verses. The particular uses follow, from the third verse to the end of the Epistle.
By the tender mercies of God — The whole sentiment is derived from Rom. i.-v. The expression itself is particularly opposed to "the wrath of God," Romans 1:18. It has a reference here to the entire gospel, to the whole economy of grace or mercy, delivering us from "the wrath of God," and exciting us to all duty.
To present — So 16:19; now actually to exhibit before God.
Your bodies — That is, yourselves; a part is put for the whole; the rather, as in the ancient sacrifices of beasts, the body was the whole. These also are particularly named in opposition to that vile abuse of their bodies mentioned, Romans 1:24. Several expressions follow, which have likewise a direct reference to other expressions in the same chapter.
A sacrifice — Dead to sin and living - By that life which is mentioned, 6:4, etc.
Holy — Such as the holy law requires, Romans 7:12.
Acceptable — Romans 8:8.
Which is your reasonable service — The worship of the heathens was utterly unreasonable, Romans 2:3, etc. But a Christian acts in all things by the highest reason, from the mercy of God inferring his own duty.
 And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.
And be not conformed — Neither in judgment, spirit, nor behaviour.
To this world — Which, neglecting the will of God, entirely follows its own.
That ye may prove — Know by sure trial; which is easily done by him who has thus presented himself to God.
What is that good, and acceptable, and perfect will of God — The will of God is here to be understood of all the preceptive part of Christianity, which is in itself so excellently good, so acceptable to God, and so perfective of our natures.
 For I say, through the grace given unto me, to every man that is among you, not to think of himself more highly than he ought to think; but to think soberly, according as God hath dealt to every man the measure of faith.
And I say — He now proceeds to show what that will of God is.
Through the grace which is given to me — He modestly adds this, lest he should seem to forget his own direction.
To every one that is among you — Believers at Rome. Happy, had they always remembered this! The measure of faith - Treated of in the first and following chapters, from which all other gifts and graces flow.
 So we, being many, are one body in Christ, and every one members one of another.
So we — All believers.
Are one body — Closely connected together in Christ, and consequently ought to be helpful to each other.
 Having then gifts differing according to the grace that is given to us, whether prophecy, let us prophesy according to the proportion of faith;
Having then gifts differing according to the grace which is given us — Gifts are various: grace is one.
Whether it be prophecy — This, considered as an extraordinary gift, is that whereby heavenly mysteries are declared to men, or things to come foretold. But it seems here to mean the ordinary gift of expounding scripture.
Let us prophesy according to the analogy of faith — St. Peter expresses it, "as the oracles of God;" according to the general tenor of them; according to that grand scheme of doctrine which is delivered therein, touching original sin, justification by faith, and present, inward salvation. There is a wonderful analogy between all these; and a close and intimate connexion between the chief heads of that faith "which was once delivered to the saints." Every article therefore concerning which there is any question should be determined by this rule; every doubtful scripture interpreted according to the grand truths which run through the whole.
 Or ministry, let us wait on our ministering: or he that teacheth, on teaching;
Ministering — As deacons.
He that teacheth — Catechumens; for whom particular instructers were appointed.
He that exhorteth — Whose peculiar business it was to urge Christians to duty, and to comfort them in trials.
 Or he that exhorteth, on exhortation: he that giveth, let him do it with simplicity; he that ruleth, with diligence; he that sheweth mercy, with cheerfulness.
He that presideth — That hath the care of a flock.
He that showeth mercy — In any instance.
With cheerfulness — Rejoicing that he hath such an opportunity.
 Let love be without dissimulation. Abhor that which is evil; cleave to that which is good.
Having spoken of faith and its fruit, Romans 11:25.
Abhor that which is evil; cleave to that which is good — Both inwardly and outwardly, whatever ill-will or danger may follow.
 Be kindly affectioned one to another with brotherly love; in honour preferring one another;
In honour preferring one another — Which you will do, if you habitually consider what is good in others, and what is evil in yourselves.
 Not slothful in business; fervent in spirit; serving the Lord;
Whatsoever ye do, do it with your might. In every business diligently and fervently serving the Lord - Doing all to God, not to man.
 Rejoicing in hope; patient in tribulation; continuing instant in prayer;
Rejoicing in hope — Of perfect holiness and everlasting happiness. Hitherto of faith and love; now of hope also, see the fifth and eighth chapters; afterwards of duties toward others; saints, Romans 12:15, etc.
 Distributing to the necessity of saints; given to hospitality.
Communicate to the necessities of the saints — Relieve all Christians that are in want. It is remarkable, that the apostle, treating expressly of the duties flowing from the communion of saints, yet never says one word about the dead.
Pursue hospitality — Not only embracing those that offer, but seeking opportunities to exercise it.
 Bless them which persecute you: bless, and curse not.
Curse not — No, not in your heart.
 Rejoice with them that do rejoice, and weep with them that weep.
Rejoice — The direct opposite to weeping is laughter; but this does not so well suit a Christian.
 Be of the same mind one toward another. Mind not high things, but condescend to men of low estate. Be not wise in your own conceits.
Mind not high things — Desire not riches, honour, or the company of the great.
 Recompense to no man evil for evil. Provide things honest in the sight of all men.
Provide — Think beforehand; contrive to give as little offence as may be to any.
 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord.
Dearly beloved — So he softens the rugged spirit. Revenge not yourselves, but leave that to God. Perhaps it might more properly be rendered, leave room for wrath; that is, the wrath of God, to whom vengeance properly belongs. Deuteronomy 32:35
 Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.
Feed him — With your own hand: if it be needful, even put bread into his mouth.
Heap coals of fire upon his head — That part which is most sensible. "So artists melt the sullen ore of lead, By heaping coals of fire upon its head; In the kind warmth the metal learns to glow, And pure from dross the silver runs below." Proverbs 25:21, etc.
 Be not overcome of evil, but overcome evil with good.
And if you see no present fruit, yet persevere.
Be not overcome with evil — As all are who avenge themselves. But overcome evil with good. Conquer your enemies by kindness and patience.