As Christians prepare to celebrate the birth of Jesus Christ, pastors are struggling to draft sermons that will make the 2,000-year-old Christmas story come alive for the faithful who pack the pews on Christmas day. They can expect a receptive audience: A recent Harris poll found that 72 percent of Americans believe that Jesus is God or the son of God and 60 percent believe that he was born of a virgin.

Such widespread Christian belief, though admittedly less robust than most pastors would like to see, is significant when considering its consequences. The Christian doctrine of the Incarnation at the heart of the Christmas story declares that God began his life on earth as a human embryo, one like us in all things but sin. The implications of that belief are profound: If God took on human flesh in its earliest stages, then human bodily life must deserve not only respect, but reverence.

Of course, more Americans profess belief in the biblical Christmas story than seriously ponder its consequences. How else to explain our facile acceptance of the idea that our minds are synonymous with our selves and our bodies are merely the matter that our minds inhabit, with no intrinsic meaning of their own?

We are, no doubt, obsessed with our bodies. We turn to cosmetics counters and diet plans to perfect our physical appearance. We chase after physical pleasures and bodily health with great vigor.

Yet we also disparage the significance of our bodies. We tend to identify our personhood with our ability to reason and will. And we believe that we can do whatever we wish with our bodies as long as we don't hurt anyone else -- anyone, that is, who counts as a person with these same abilities to reason and will.

These assumptions reflect a mind-body dualism that denigrates the body, and they are rampant in our culture. They underlie everything from our obsession with cosmetic surgery ("I want the world to see the real me") to our attitudes about sex ("It's just physical") to our growing acceptance of euthanasia for the demented and comatose ("Why not kill him? He's already gone anyway").

These ideas also powerfully shape our debates over beginning-of-life issues. Abortion-rights activists dismiss concerns about the killing of a fetus by arguing that it is "just a blob of tissue." Supporters of embryonic stem cell research say we need not trouble ourselves over the destruction of an embryo because it is "just a clump of cells."

Reason alone can refute these claims. The human embryo, like the human fetus, is a genetically unique, self-directing individual who looks exactly as a human person should look in her earliest stages of life and exactly as each of us looked at her age. The size, location and frailty of her body does not nullify her right to life.

While reasoned arguments are sufficient to defend these nascent human lives, the Christian faith professed by more than three-quarters of Americans offers yet more grounds to do so. That faith says that God became incarnate in a human body and passed through every stage of human development, including the embryonic, in order to redeem human beings, body and soul. By doing so, he has endowed the human body in all its developmental stages with intrinsic dignity.

In a campaign year that has featured an inordinate amount of talk about the divisive potential of religion, it seems more fitting than ever that Christians focus on what the Christmas story says about the dignity that unites all of God's children, no matter how old, how sick, or how small.

-- Colleen Carroll Campbell, a former White House speechwriter, is an Ethics and Public Policy Center fellow, St. Louis Post-Dispatch columnist, host of EWTN's "Faith & Culture," and author of The New Faithful: Why Young Adults Are Embracing Christian Orthodoxy (Loyola Press, 2002).