Someone has commented that while generations past may have lived like there was no such thing as sex, our generation lives like there is nothing but sex!
Our culture is one that sees sex a lot like fast food. It’s a basic human “appetite”; why shouldn’t we indulge it whenever want, however we want, as is convenient for us? It’s only natural, right?
The interesting thing about this passage is that it ties sex into what it means to be a person. People were created for relationships with God and one another where, to borrow a phrase from Immanuel Kant, we always treat persons (including ourselves) as ends in themselves, never merely as a means to our own ends. To take sex so casually that it is a mere matter of ends justifying the means is to violate the Christian view of what it means to be a person.
That is why casual sex is very different than fast food. It does not honor people as people, but uses them only for own pleasure and gratification. And by the way—that is the problem with sexual fantasy as well. It reinforces ways of thinking that use people to the point where it becomes our most natural way to approach them.
This is also why in the Christian tradition sex is reserved for marriage. In marriage, sex is more than mere physical coupling. It is part of that unique, lifelong process, born in public commitment before God and our community, to love another so deeply that two become one not just in body, but also in heart and mind and soul.
So we are to glorify God by using our body as an expression of what we believe to be true, right and wrong. And even as that principle so clearly pertains to sex, I hope you can see how it can be applied in a much broader sense to our life in general.
Once again, I like how The Message puts it:
Or didn't you realize that your body is a sacred place, the place of the Holy Spirit? Don't you see that you can't live however you please, squandering what God paid such a high price for? The physical part of you is not some piece of property belonging to the spiritual part of you. God owns the whole works. So let people see God in and through your body.