Paul is speaking from experience. Here is a man who was rejected, tempted, persecuted, beaten, jailed, shipwrecked, stoned. Paul also had all the cares of the church laid on him. Now he’s saying to us, “Do you want to know how I came to be content in whatever condition I was placed, how I came to find true rest in Christ? Here is the path, the secret to appropriating your heavenly position: Present your body as a living sacrifice to the Lord.”
The Greek root for “living” here suggests “lifelong.” Paul is talking about a binding commitment, a sacrifice that’s made once in a lifetime. Yet, don’t misunderstand; this isn’t a sacrifice that has to do with propitiation for sin. Christ’s sacrifice on the cross is the only worthy propitiation: “Now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself” (Hebrews 9:26).
The sacrifice Paul describes is one that God takes great pleasure in, precisely because it involves the heart. What is this sacrifice? It is one of death to our will, of laying aside our self-sufficiency and abandoning our ambitions.
When Paul exhorts, “Present your body,” he’s saying, “Draw near to the Lord.” Yet, what does this mean, exactly? It means drawing near to God for the purpose of offering our entire selves to him. It means coming to him not in our own sufficiency, but as a resurrected child, as holy in Jesus’ righteousness, as being accepted by the Father through our position in Christ. The moment you resign your will to him, the sacrifice has been made. It happens when you give up the struggle of trying to please God on your own. This act of faith is the “reasonable service” Paul refers to. It’s all about trusting him with our will, believing he’ll provide all the blessings we need.