The appeal is that the readers offer their bodies as sacrifices, a suggestion whose force would be more obvious to Paul’s first readers than to most modern students. First-century people were familiar with the offering of sacrifices, whereas we are not. They had stood by their altars and watched as an animal was identified as their own, as it was slain in the ritual manner, its blood manipulated, and the whole or part of the victim burned on the altar and ascended in the flames to the deity they worshipped. To suggest that they themselves should be sacrifices was a striking piece of imagery. Paul’s verb, offer, could be used of offerings of various kinds (it is used, e.g., in 6.13, 16, 19), but it was a technical term for the offering of a sacrifice.
From: The Epistle to the Romans by Leon Morris; The Pillar New Testament Commentary series (Grand Rapids: William B. Eerdmans Publishing Company, 1988), p. 433.
Leon Morris (1914-2006) was an Australian New Testament scholar and educator. He was a prolific author, whose best-known work is probably The Apostolic Preaching of the Cross (1956).