The last phrase Paul uses to describe this sacrifice is this: “your spiritual service of worship.” Again, the word for “service of worship” here is the Septuagint’s word to describe the temple worship of the Old Testament. The word spiritual here is a rich word. It’s the word logikos, which means logical or reasonable. Now Paul is using Greek philosophy against itself. In Greek thought, logic was a spiritual activity, a work of the soul. So this offering of the body is a spiritual activity. Again, notice that Christian thought (the truth) opposes the idea that the body is bad or that it would be good to be a purely spiritual being, i.e. to be “free” from the body.
The use of the word logikos also carries another idea from Greek philosophy. It’s the word you would use to talk about the true nature or essence of a thing. So the idea or essence, or logikos, of, say, a horse was more important than any particular horse. Paul is saying here that the offering of one’s living body is the essence of true worship, and thus the ONLY life that makes any sense as a therefore to the Gospel.
You know, we call a lot of things worship. We call our Sunday morning meeting a worship service. We call singing worship. We call prayer worship. We call the reading of scripture worship. We call the exposition of scripture by a gifted preacher worship. We call daily quiet times in the word, and our day to day obedience, worship.
But if you come to church and sing and pray and read and listen, but don’t present your body to God a sacrifice, you are not worshipping. You are not giving God his due. If you spend time in the word every day and work hard to obey its commandments, but you don’t make yourself available to God to do with as he wishes, you are not worshipping. You are not giving God his due. You are not living a truly Christian life. The essence of the Christian life—the only life that is a reasonable therefore to the Gospel—is a total radical commitment of availability to God.
That is such a high standard that you may find it impossible and be discouraged. But let me say to you that while it is high, it is also simple, and by the Spirit who dwells in you, it is not at all impossible. And no matter what happened yesterday, it is possible today for every Christian to renew this commitment to availability, to present himself or herself again a living sacrifice.
I’m thankful that the Lord said “take up your cross daily,” because it means that if I lost track of my commitment to availability yesterday, I can take it up again today. Howard Hendricks said, “The trouble with living sacrifices is that they are constantly crawling off the altar.” That is, I think, why we have a worship service every week, so that we are constantly reminded that the life we are called to live is a life of radical availability to God.