Some Christians (most notably Sarah Palin) oppose plans to build an Islamic community center and mosque in New York City, two blocks away from Ground Zero. Some Christians support it. I support it, after initial worries that I'll explain.
As an American, I love the symbolism: a building devoted to a religion that many Americans and millions around the world practice peacefully, so close to a place where terrorists claiming that religion tried to make a monument to hate. The attackers' message was that the United States is hostile towards Islam as a whole; this would be a great way to prove them and their followers wrong.
As a religious person, though, when I saw heard the phrase "Ground Zero mosque" in a headline, I figured it was about a mosque to be built on the site of Ground Zero itself as a memorial, and that made me squeamish. Not because a mosque doesn't belong on the site of a national public memorial—but because no house of worship belongs there. Putting a house of worship on public property amounts to a government endorsement of a religion. That's why I oppose nativity scenes in public plazas and the Ten Commandments in city halls. And in these cases what I'm worried about is the independence of religion: I worry government will succumb to exploiting religion and religious devotion for its own purposes. Given that a mosque near Ground Zero would have a huge political upside for the U.S., the risk is real.
But then I learned that the mosque wouldn't be on Ground Zero itself, but on private property down the street (which opponents are now cynically trying to get landmarked to derail the plans), and I felt better. This would be a great sign of the health of religious freedom in this country. And religious freedom means that religion doesn't use government for religious purposes, and government doesn't use religion for political purposes.