The nation's three largest denominations oppose federal funding for research, but other groups voice support.
President Bush and Pope John Paul II, meeting today in Rome, have taken the same stance on one of the most controversial and consequential issues in human history: the use of human embryos in research that results in their destruction.
But soon the American leader will decide whether to stick with his strong campaign position against such research, or to compromise and permit federal funding for exploration that scientists say holds tremendous potential to cure debilitating illnesses.
For the Roman Catholic Church, as well as the nation's other two largest denominations, Southern Baptist and United Methodist, the decision represents a crucial moment - in terms of both this presidency and America's approach to the biotech era.
Still, the religious community is not of one accord on the issue. Some, such as the Presbyterian Church USA and the Reform Jewish movement, have come out in favor of limited embryo-based research. The disparities are rooted in different views about key elements of the debate - when human life begins, whether a desirable outcome justifies controversial means, and what this decision could mean for future ones involving the biotech world.
Ever since the cloning of Dolly the sheep, religious communities have been grappling with the implications of this era - a task greatly complicated by rapid technological advances. Last week, for example, two private labs announced they are creating human embryos for research by cloning and other methods - an act long seen as taboo.
This full-speed-ahead approach to genetic technologies, as well as the moral crossroads of destroying early human life to save other lives, has led the three largest US denominations to oppose US funding for embryonic stem-cell research.
"This debate is about the dignity due a human embryo, but also about where the limits are," says Jaydee Hanson, spokesman for the United Methodist Church. "What we are really arguing about is whether the public at large has a role in saying what kind of research should go forward rapidly and what kind shouldn't."
A recent Gallup poll shows 57 percent of Americans say they don't know enough about embryonic stem-cell research to support or oppose it.
Still, 54 percent believe the research is morally wrong, but 69 percent say it may be necessary.