"I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship. Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect."
Our duty to the Creator is to offer him our worship, our spiritual worship as the text says. When we do this as we ought, we are offering our bodies as a living sacrifice which is pleasing and acceptable to God. What exactly does it mean for us to offer our bodies as a living sacrifice? It means first and foremost, to discern the good, acceptable, and perfect will of God. We do this so that we do not become conformed by the world, but are instead transformed by the renewal of our minds. Doing this is what it means to offer our bodies (and minds) as living sacrifices. This hits home for me.
I am not naturally a wise and discerning person. I am a lazy thinker, a thought drifter, and seldom discern anything without major effort. So when I read that the way I am to offer my body (and mind) as a living sacrifice to God is through discerning his will, I feel the weight of falling short once again.
Discernment carries with it the idea of discrimination, or separation. It is placing space between what is good from what is evil, what is acceptable from what is unacceptable, and what is perfect from that which is imperfect. Not only does discernment involve separation, but the clinging and adhering to that which is found to be the good, acceptable, and perfect, and the abstaining from the evil, unacceptable, and the imperfect.
The word good means, well; good. The term acceptable means well pleasing. And the word perfect means complete and brought to an end. The discerning person is the individual who's mind is always discriminating between ideas. Like Jesus separating the sheep from the goats, this individual is placing everything in one category or another. After each idea is brought against scripture to determine it's worth, the discerning person then embraces that which is in the good category, and abstains from that which is in the evil. This entire act is one of worship. It is how we offer our body as a living sacrifice. It is how we do not become conformed to the world. And it is how we offer God our spiritual worship.