therefore. “Therefore,” that is, in view of all the great doctrinal truths expounded in Romans 1-11, we should live as described in Romans 12-16. As is true in most of Paul's epistles, he first lays the doctrinal foundation, then draws out the practical consequences.

living sacrifice. The key to real Christian living is dying to the world and living unto Christ. This great theme appears repeatedly throughout the New Testament.

reasonable service. “Reasonable” is the Greek logikos, from which we derive our word “logical,” and “service” is the Greek latreian, referring to service as a priest. We have been made “an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ” (1 Peter 2:5), and it is perfectly logical that we render such lifelong service.

to this world. We are predestined ultimately to be “conformed to the image of [God's] Son” (Romans 8:29); therefore it is eminently logical that we should not be conformed to this world, which is at “enmity with God” (James 4:4). See also xTerm 2:15.

renewing of your mind. Our “renewed minds” were once “blinded” by the “god of this world,” Satan (2 Corinthians 4:4). Now they should be, and can be, in harmony with and guided by “the mind of Christ” (Romans 11:34; 1 Corinthians 2:16).prove. Here is the key to knowing God's will.

many members in one body. There are three enumerations of the individualized gifts of the Holy Spirit in Paul's epistles. See also 1 Corinthians 12:4-11 and Ephesians 4:11.

one body in Christ. All three listings of the gifts of the Spirit use the analogy of the body with its many members, indicating that all together comprise, in a spiritual sense, the body of Christ.

given to us. It is significant that the three listings of the gifts all differ from each other. This means that no listing is complete; in fact, some gifts were needed only for a time (e.g., that of being an apostle), and others would be needed in later periods of history. The Spirit would bestow particular gifts as needed (1 Corinthians 12:7, 11), not according to personal preference.

proportion of faith. “Proportion” (Greek analogia) is essentially a mathematical term. One with a prophetic gift (that is, ability to transmit divinely inspired messages) was to be able to use such a gift effectively in direct proportion to the strength of his faith.

ministry. “Ministry” (Greek diakonia, from which we get our word “deacon”) refers to “service” in the form of mundane “helps.” In contrast, there is priestly service (Romans 12:1) and also slave service (Romans 12:11).

teacheth. The only gifts included in all three listings (see note on Romans 12:4) are the gifts of prophecy and teaching. The gift of prophecy would eventually “cease” (1 Corinthians 13:8), evidently when the New Testament was completed, but the gift of teaching would continue to be needed in every church in every age.

dissimulation. That is, “hypocrisy.”

business. This term refers not just to making a living, but to all aspects of life. Compare Ecclesiastes 9:10; Colossians 3:23; Ephesians 6:7.

serving. The Greek word here is douleuo, in contrast to the other words speaking of “serving” in this chapter. See note on Romans 12:7. The service here is that required of slaves. Before conversion, we were bond-servants to sin, but the Lord Jesus has purchased us with His blood, so we are now His bond-servants (1 Peter 1:18-19; 1 Corinthians 6:19-20; Romans 6:16).

wise in your own conceits. This is the last of six occurrences of this biting phrase. See also Proverbs 26:5, 12, 16; 28:11; Romans 11:25. Pride of one's position, intelligence, race, status or wealth constitute ungodly conceit, and so do laziness and foolishness, as seen in these passages.

it is written. Romans 12:19-20 is derived from Deuteronomy 32:35 and Proverbs 25:21-22, respectively. Note also Christ's command in Matthew 5:43-47.