Romans 12: part 1

1 I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service. 2 And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.

Service (Gr. latreia, lit. “bow down”) is better translated “worship”. This is the worship of God through the whole life of the Church, beginning with a renewed mind and integrity of heart. In union with Christ, we are brought from worshipping the creature to worshipping the Creator in all we do. This worship is:
(1) Physical: Bodies suggests both the physical aspect of human nature and human nature generally – ourselves.
(2) Living: a contrast to the Old Covenant under which sacrifices were put to death. Under the New Covenant, to die is also to be resurrected. Sacrifice is not a final act but the firstfruit, the foundation, for all other spiritual fruit.
(3) Virtuous (holy, acceptable): OT sacrifice was unacceptable and temporary. Animals are not substitutes for humanity or true holiness.
(4) Reasonable, or “spiritual” (Gr. logike): Though worship of God has its logical side, it is more than this – even as Christ, the Logos, possesses reason but is far more than reason. To be reasonable  is to live according to Christ, with renewed hearts and minds.

Faithful relationship to God changes our relationship to the world. (1) We renounce the pretenses of “this present evil age.” Conformed to this world is to be identified with and shaped by the world’s values and pleasures. (2) We are transformed, starting with the inward man, the mind, by virtue, the keeping of God’s commandments. Mind here is more than the rational faculty; it is the highest faculty of human nature: “The eyes of your heart,” by which one sees and comprehends God.

Romans 7

1 Or do you not know, brethren (for I speak to those who know the law), that the law has dominion over a man as long as he lives? 2 For the woman who has a husband is bound by the law to her husband as long as he lives. But if the husband dies, she is released from the law of her husband. 3 So then if, while her husband lives, she marries another man, she will be called an adulteress; but if her husband dies, she is free from that law, so that she is no adulteress, though she has married another man. 4 Therefore, my brethren, you also have become dead to the law through the body of Christ, that you may be married to another—to Him who was raised from the dead, that we should bear fruit to God. 5 For when we were in the flesh, the sinful passions which were aroused by the law were at work in our members to bear fruit to death. 6 But now we have been delivered from the law, having died to what we were held by, so that we should serve in the newness of the Spirit and not in the oldness of the letter. 7 What shall we say then? Is the law sin? Certainly not! On the contrary, I would not have known sin except through the law. For I would not have known covetousness unless the law had said, “You shall not covet.”^[a] 8 But sin, taking opportunity by the commandment, produced in me all manner of evil desire. For apart from the law sin was dead. 9 I was alive once without the law, but when the commandment came, sin revived and I died. 10 And the commandment, which was to bring life, I found to bring death. 11 For sin, taking occasion by the commandment, deceived me, and by it killed me. 12 Therefore the law is holy, and the commandment holy and just and good.

If we were held knowledgeably under sin by the law, then by the fulfillment of the law and the Incarnation, death, and resurrection of Christ, we are freed from it.  So that we may participate in the life of God.

13 Has then what is good become death to me? Certainly not! But sin, that it might appear sin, was producing death in me through what is good, so that sin through the commandment might become exceedingly sinful. 14 For we know that the law is spiritual, but I am carnal, sold under sin. 15 For what I am doing, I do not understand. For what I will to do, that I do not practice; but what I hate, that I do. 16 If, then, I do what I will not to do, I agree with the law that it is good. 17 But now, it is no longer I who do it, but sin that dwells in me. 18 For I know that in me (that is, in my flesh) nothing good dwells; for to will is present with me, but how to perform what is good I do not find. 19 For the good that I will to do, I do not do; but the evil I will not to do, that I practice. 20 Now if I do what I will not to do, it is no longer I who do it, but sin that dwells in me.
21 I find then a law, that evil is present with me, the one who wills to do good. 22 For I delight in the law of God according to the inward man. 23 But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members. 24 O wretched man that I am! Who will deliver me from this body of death? 25 I thank God—through Jesus Christ our Lord!
So then, with the mind I myself serve the law of God, but with the flesh the law of sin.

This passage I think is often quoted with confusion, probably because of the play on words that St. Paul uses and its translation into English.  I also find that verse 18 is commonly used to support the belief that there’s nothing good inside a person, however, that’s complete nonsense.  The passage is depicting a contradiction within the person to will good and to do good or evil.  The task is on our part to strengthen our will so that we may overcome our fleshly desires and act on our will, which is what God wants. This is really just a summary of the Christian life.  We constantly battle against ourselves and our passions to become more Godly and participate in the life of God, the life of the Church, etc.  Indeed, we need to thank God for his grace and mercy in helping us along this path.

By the way, the word mind, in the greek, I just looked up and it’s the word Nous.