12:1

Therefore: Paul apparently uses this expression to link what he discussed in the preceding part of his letter with what he is about to say. In effect, he is saying: “In view of what I just explained to you, I appeal to you to do what I will tell you next.” Paul had discussed the opportunity open to both Jews and Gentiles to be declared righteous before God by faith, not by works, and to be corulers with Christ. (Ro 1:16; 3:20-24; 11:13-36) Beginning in chapter 12, Paul urges Christians to be thankful and to demonstrate their faith and gratitude by obeying God and by living a life of self-sacrifice.

brothers: See study note on Ro 1:13.

present your bodies: Under the Mosaic Law, the Israelites slaughtered animals and presented these dead animals as sacrifices. Such sacrifices could be offered only once. In contrast, a Christian continually presents his body, his whole being, as a living sacrifice. This “sacrifice” includes the person’s mind, heart, and strength​—all his faculties. It is an act of total dedication involving every aspect of his life. Paul adds that a Christian’s sacrifice of himself must be holy and acceptable to God. This may allude to the fact that Israelites were never to offer unacceptable animal sacrifices, such as lame or deformed animals. (Le 22:19, 20; De 15:21; Mal 1:8, 13) Likewise, Christians must live a clean life in harmony with what God approves in order for their sacrifices to be acceptable.

a sacred service: Or “a worship.” The Greek word used here is la·treiʹa and refers to acts of worship. In the Christian Greek Scriptures, this noun is sometimes used in connection with the Jewish system of worship based on the Mosaic Law. (Ro 9:4; Heb 9:1, 6) However, here Paul uses it in connection with Christian worship. The related Greek verb la·treuʹo (“to render sacred service”) is used both with regard to worship according to the Mosaic Law (Lu 2:37; Heb 8:5; 9:9) and Christian worship (Php 3:3; 2Ti 1:3; Heb 9:14; Re 7:15). At Ro 1:9, Paul showed that an important feature of his sacred service was “in connection with the good news about [God’s] Son,” that is, the preaching of this good news.

with your power of reason: The expression “power of reason” is translated from the Greek word lo·gi·kosʹ. In this context, it conveys the idea of sacred service rendered in a “logical,” “rational,” or “intelligent,” manner. One lexicon defines it as “pert[aining] to being carefully thought through, thoughtful.” Christians are often called on to weigh Bible principles carefully. They need to understand how Bible principles relate to one another and to decisions under consideration. They can use their God-given power of reason, or thinking abilities, to make balanced decisions that will have Jehovah’s approval and blessing. This way of worship was a change for many Jews who had become Christians. They had previously lived their life following the many rules dictated by tradition.