When speaking about sacrifice, we need to distinguish between two different sorts: a common or generic sacrifice and a "living" sacrifice. In the former, one thing is given up for a different thing, and often this second thing is in some way thought to be of a greater value than the thing given up. So, for example, in baseball, a batter might hit a fly ball and get out on purpose to give a runner the chance to score a run. Alternately, a member of the Secret Service may take a bullet for the president, thus sacrificing his or her life. One thing is given up, done away with, even destroyed for the increase, benefit, or continued existence of another. This for that.
A living sacrifice, on the other hand, is different, and a hint to this difference can be found in certain forms of the Eucharistic prayer in the Episcopal church. Here we speak of a "sacrifice of praise and thanksgiving." Is this the same thing as a generic sacrifice? What is given up here, and what benefit is gained? Surely we do not mean here a sacrifice of time, as if the time it takes to say the Eucharistic prayer is given up for the benefits of the Eucharist or some means to glorify God. No, what is sacrificed is, in a way, our attention or self-focus, which is enlivened toward an active thanksgiving for the spirit of life. What is important here, in our present context, is that the thing "sacrificed" is not given away or destroyed; instead, it is the very thing itself that is enlivened and made better. Our attention is lifted up to the presence of God through its act of sacrifice.
The key difference here between the two types of sacrifice is the structure of death and resurrection. These are not two different concepts joined together, but two parts of a system that must go together; without resurrection, death leads to a mere destruction. This is the case of generic sacrifice. Here there is an end, a cessation of one thing, for the benefit of another. Altruistic, seemingly, for the one benefited, but what of the one who is sacrificed? Too often has victimization masqueraded as false sacrifice, where something is used up and forgotten while another can climb higher. This is not altruism but ignorance and oppression, and our faith, as Christ taught it, has never been about allowing others to be destroyed and abandoned, no matter what the cost.
Living sacrifice, on the other hand, has the opposite effect: the increase of life. Here a thing is raised up and made greater, not in spite of itself but as itself. A parent sacrifices his time and money to raise a child, or a doctor sacrifices her time and intelligence to learn to heal others. In each, nothing is destroyed, but is raised to be more than it was before. A new meaning of time and attention is found in the grace of raising a child, and intelligence takes on a fuller meaning when directed to the care of the sick and injured. One finds truer uses of time, attention, intelligence, and other aspects of the self only when one is able to sacrifice them.
In writing of sacrifice as a bettering of the self, however, I do not want to suggest that it is easy, or simple, or even kind. True sacrifice still requires a death, and the promise of resurrection does not take the fullness of that death away. Death, in whatever form, often comes at great personal cost. But death is not the end, and we (not something or someone else) will survive it. That is the great promise of our faith.
Living sacrifice, then, is about death and resurrection. Such sacrifice is not about mere change for change's sake, nor the success of something deemed better over that deemed lower. Living sacrifice is about growth, the development of one thing, as itself, while retaining its essence, beyond itself. It is an image of Christ, who in his incarnation joined two things at once, human and divine, and in his death and resurrection opened this way for us all.
Why is this important? In our current culture, we can often confuse self-sacrifice as self-destruction. We call on Christians to bear their cross, even to death, but we forget to remind them that self-denial is not self-hatred and self-negation. God leads us to conversions of ever-increasing depth, and we are often led by things we love. Not always, but sometimes. God does not want for us to turn around after conversion and sling hatred at those things that brought us a deeper sense of God's presence, for often it was Christ who brought us there. As we continue to teach Christian discipleship, we must not teach people to become victims of their acts of sacrifice, but rather to join our very humanity (which is also Christ's humanity) with God's divinity.