Paul calls us – that is, Christians – “rational creatures.” As rational creatures, we owe God our “bodies as a living sacrifice.” I like Paul’s use of the plural when he refers to the bodies of Christians and the singular when he refers to the living sacrifice. Paul often refers to Christians as members of the singular “body of Christ.” The whole body of Christ, i.e. the Church is the “living sacrifice” we owe to God. Together we must “offer up [our] bodies” that are “consecrated to God and worthy of His acceptance.” Worship is a mutual undertaking, i.e. worship is meant to occur among fellow Christians. As “rational creatures,” Paul expects us to understand these truths. He calls us to worship together as one; to offer our bodies together as one, united “living sacrifice.” We are the body of Christ, the Church of which He is the head.
“And now, brethren, I appeal to you by God’s mercies to offer up your bodies as a living sacrifice, consecrated to God and worthy of his acceptance; this is the worship due from you as rational creatures.”