1 Samuel 14; Romans 12; Jeremiah 51; Psalm 30
among the major points that Paul has been making in his letter to the Romans is the sheer gratuity of grace, the amazing measure of mercy that has won Jews and Gentiles alike. Alike we are guilty; alike we are justified, forgiven, renewed, owing to the measureless mercy of God.
In view of such mercy, Paul urges his readers “to offer [their] bodies as living sacrifices, holy and pleasing to God” (Rom. 12:1). We are so familiar with this verse that its strangeness no longer strikes us. In the ancient world, a sacrifice must be living to begin with, of course, but what makes it a sacrifice is that it is put to death. But Paul wants us to offer our bodies as living sacrifices, that is, as ongoing “sacrifices” that respond to God’s mercy by devoting ourselves, not least our bodies, to him. Such sacrifices are “holy and pleasing to him.” The idea is that in the light of the matchless mercy we have received, the least we will want to do is to be pleasing to him.
Such sacrifices constitute our “spiritual worship.” The adjective rendered “spiritual” embraces both “spiritual” and “reasonable” or perhaps “rational.” These are not sacrifices offered in a temple, begun with a bloodletting, continued with a burning of the body, and completed in selective eating of the meat. New covenant worship is no longer bound up with the temple and the ritual demands of the Sinai covenant. The way we live, in response to the mercy of God, lies at the heart of Christian worship.
If we want to know what this looks like, the second verse spells out the practicalities in principle, and the ensuing verses give them concrete form. To offer up our bodies in living sacrifice to God means conforming no longer to the pattern of this world, but being transformed by the renewing of our minds (12:2). In other words, what is at issue is not merely external behavior, while inwardly we remain in the grip of carefully masked hate, lust, deceit, envy, greed, fear, bitterness, and arrogance. What is at issue is the transformation of the way we think, bringing our minds in line with the ways and Word of God. That will produce all the change in behavior that is necessary and wise—and that change will be radical. By this fundamental transformation, we shall be enabled to test and approve in our own experience what God’s will is—and find it “good, pleasing and perfect” (12:2). In the light of Romans 8:9, doubtless the motivating power for this transformation is the Spirit of God. But that magnificent truth does not absolve us of resolve; it empowers it.
 Carson, D. A. (1998). For the love of God: a daily companion for discovering the riches of God’s Word. (Vol. 1, p. 25). Wheaton, IL: Crossway Books.