Rom 12:1 this chapter St. Paul begins his second part, in which he gives us most excellent lessons of morality, after which every Christian should aim to form his life, and thus resemble Jesus Christ and his saints. (Haydock) --- That you present your bodies a living sacrifice. And how must this be done? says St. John Chrysostom, hom. xx. Let the eye abstain from sinful looks and glances, and it is a sacrifice; the tongue from speaking ill, and it is a sacrifice, &c. --- Your reasonable service, or worship,[1] from you; nothing being more reasonable, than for men to serve God with their souls and bodies, &c. (Witham)

===============================

[BIBLIOGRAPHY]

Rationabile obsequium, Greek: logiken latreian.

Rom 12:2 care, lest you imitate the practices of worldlings. Let your heart, your ambition, carry you to heaven: ever despise those things which the world admires, that every one may see by your actions that you are not of the society of worldlings, and have neither regard nor friendship for them. (Calmet) --- Transform yourselves into new men, by the renewal of your mind, that you may discern on all occasions, what is most perfect, most pleasing and acceptable to God. (Bible de Vence)

To be wise unto sobriety. Not pretending to be more wise, or more knowing than you are. --- As God hath divided to every one the measure of faith. The sense by what follows is, that every one make the best use, for the glory of God, and the good of his neighbour, of the gifts and graces which he hath received together with the faith of Christ; i.e. of prophecy, or the gift of interpreting past prophecies, or of foretelling things to come, of exhorting, of ministering as to those functions which belong to the ministers of the gospel, &c. (Witham)

Rom 12:9 apostle does not here prohibit that defence, by which a person, either by word or action, preserves himself from injury. This he could not condemn, since he had so often recourse to it himself, as we read in the Acts of the Apostles: and in the second [epistle] to Timothy, he writes: "In my first defence no one was with me." Be he only forbids that revenge which a person takes of his neighbour, by private means, without having recourse to legal authority. (Estius)

Communicating [2] to the necessities of the saints. Making them partakers of what you have, by relieving them. (Witham)

===============================

[BIBLIOGRAPHY]

Communicantes; Greek: koinonountes. Koinonein is often used by St. Paul for making others sharers by giving to them.

====================

Condescending to the humble, in the spirit of charity and sweetness. See Luke ii. 48. (Witham)

If it be possible,....have peace with all. That is, if it can be without prejudice to truth or justice, &c. And even when others wrong you, seek not to revenge yourself, but leave you cause to God. Do good offices even to those that do evil to you. (Witham)

Give place to wrath. That we do, says St. John Chrysostom, when we leave all to God, and endeavour to return good for evil. (Witham)

Thou shalt heap coals of fire on his head. This figurative way of speaking is differently expounded. Some say, inasmuch as by this means thou shalt make him liable to greater punishments from God. Others, as St. Jerome and St. Augustine, by coals of fire, understand kindnesses and benefits, which shall touch the heart, and inflame the affections even of thy enemies, which shall make them sorry for what they have done, and become thy friends. (Witham)

Rom 12:21 is the apostle's conclusion of the foregoing instructions. Be not overcome by the malice of thy enemy, so as to wish to revenge thyself, without leaving all to the just judgment of God; but overcome his malice by thy kindness. This is complied with, when upon occasion of injuries received we always return a kindness, and in proportion as the malice of our enemies increases, our spirit of benevolence should also increase. (Estius)