If you have ever been asked to make a "sensible" decision, you probably knew that meant you were to give it a little extra thought, not just acting upon a whim or fancy. You are "aware" of what is happening and then you are making actively engaged decisions based on this awareness. There is something about serving God which is kind of sensible - because we actively engage in this relationship with him. Yet, there are parts of serving God we cannot "over-think" - because then the relationship becomes kind of just a "religious pursuit" and not a relationship. The idea of presenting our bodies to Christ as a living sacrifice is kind of something we cannot pour a whole lot of thought into or we will get kind of "weird" in our beliefs! First of all, God doesn't actually want any of us "burning our bodies" on an altar in a literal sense. What he does want is this idea of yielding something which we treat with so much attentive focus to him so he can occupy it and bring about great things in it! Our bodies are pretty much top priority for us. If you don't believe me, think about the last time you were hungry and what you did about that. You probably marched off to the pantry, kitchen, or took a trip to the local eatery to get that hunger under control. You respond to your body's demands, don't you? You might not treat it "well", but you respond to it and give into it so many times. God wants us to take this thing which receives all this attentive focus from us and present it to him - to be of service to him. In other words, we enter into this relationship asking God not what he will do to please us, but what it is we can do to bring honor and glory to him.
Dear friends, God is good. So I beg you to offer your bodies to him as a living sacrifice, pure and pleasing. That’s the most sensible way to serve God. Don’t be like the people of this world, but let God change the way you think. Then you will know how to do everything that is good and pleasing to him. (Romans 12:1-2 CEV)
Changing the way we think is probably harder than yielding our bodies to him, though. At first, our way of thinking is kind of warped - focused pretty intently on what it is in this life we can get out of it to please ourselves, fulfill our desires, etc. When we come to Christ, this focus begins to change a little and we find ourselves gradually focusing less and less on what "we" want and more and more on what it is God wants to do through us. This is when we truly know we have presented our "bodies" as a living sacrifice - when we begin to take backseat and Christ becomes preeminent in our lives.
Too many times we think our thoughts are our responsibility. If we examine our passage again, we find it is God who sets about to change the way we think - because our patterns of thinking are contrary to his. We actually need to be "schooled" in a new way of thinking about ourselves, our abilities, and about others around us. Before Christ changes how it is we process our thought, we probably are a little too self-absorbed and self-focused, even for our own good! When he begins to restructure our thought processes, we begin to observe the things which were pretty much consuming our thoughts are gradually changed to seeing others through a different "set" of values. We actually begin to truthfully value another when Christ becomes central in our lives. Before he does this, each person in our lives is merely a means by which something in "us" is met.
When God restructures our thought life, we find the things in others we appreciate so much - not because of how much they will meet one of our needs, but because we see how unique their gift is in our lives. Some will speak "into" us and keep us moving in the right direction - something we didn't fully appreciate before because we might have seen it as "meddling". Others will lead by example - something we didn't fully embrace before because we were too consumed with being right ourselves we couldn't believe anybody else could live as well as we were living.
If we are really careful about examining scripture right from the beginning of the book, we will certainly see this whole concept of "relationship" woven into each and every account, prophesy, and purposefully written page. Why is this important to us? If we are to truthfully "offer" anything to another it is because we appreciate the value of this thing called relationship. If we are to earnestly and sincerely give to another, it is only because there is some measure of relationship established. Sure, we can "give" to strangers, but where there is relationship established, the "giving" takes on new meaning. There is a value built in the relationship when one yields to another. God doesn't ask anything of us he has not already done himself! He has given much for the benefit of those who he calls into relationship with him. In turn, he asks only that we give of ourselves - not our efforts - but our lives.
In giving our bodies as living sacrifices, we are not giving our efforts, but we are yielding our thoughts, attitudes, and intent to him. In so doing, he is free to begin to create within us the things which will truly bring us deep satisfaction and great peace. Just sayin!