Some of us — in my case, a political conservative and evangelical Christian — are getting a queasy feeling when it comes to the presidential campaign of former Arkansas governor Mike Huckabee, and much of it has to do with his use of faith in this political campaign.

Many who don’t know Huckabee were initially impressed with him, me included. He comes across as authentic and likable, humorous and self-deprecating. He is an excellent debater and a first-rate speaker. But if you look closely, a disturbing pattern emerges.

In Iowa, Huckabee advertised himself as a “Christian leader.” A few months ago, when speaking to a large gathering of social conservatives in Washington, he told them, “I think it’s important that the language of Zion is a mother tongue and not a recently acquired second language.” When asked to explain his surge in the polls, he answered, “There’s only one explanation for it, and it’s not a human one. It’s the same power that helped a little boy with two fish and five loaves feed a crowd of 5,000 people.”

Then came his comments to Zev Chafets, a contributor to the New York Times Magazine, in which the former pastor, who has a bachelor’s degree in religion and has worked on a master’s degree in theology, asked Chafets, “Don’t Mormons believe that Jesus and the devil are brothers?” After criticism, Huckabee apologized to Mitt Romney for injecting this matter into the campaign and said he thought his comments wouldn’t find their way into print.

And now Huckabee is running a political ad in Iowa in which he insists that a few weeks before the Iowa caucuses, the linchpin of his presidential hopes, it’s time to “pull aside from all of that,” meaning politics, because “what really matters is the celebration of the birth of Christ.”

This is a man who, in 1998, when explaining to a Baptist pastors conference why he got involved in politics, answered, “I got into politics because I knew government didn’t have the real answers, that the real answers lie in accepting Jesus Christ into our lives. . . . I hope we answer the alarm clock and take this nation back for Christ.”

Now isn’t that odd — a former pastor who leaves his ministry so he can get involved in politics because he “knew government didn’t have the real answers.”

Some of these episodes are by themselves unproblematic; others are more troubling. They are certainly different in degree, and even in kind, from what President Bush, an evangelical Christian, has said. And taken together, they raise a concern: Is Mike Huckabee, a man of extremely impressive political gifts and shrewdness, playing the Jesus card in a way that is unlike anything we have quite seen before?

This question is difficult to answer because we are dealing with motivations of the heart. The only thing we can reasonably do is judge an individual by what he says — and Huckabee is saying a lot that deserves scrutiny.

Invoking one’s faith is not unprecedented in American politics and is not, by itself, disconcerting. It can even be reassuring. But it is also fraught with danger. If certain lines — inherently ambiguous lines — are crossed and faith becomes a tool in a political campaign, it can damage our civic comity and our politics and demean our faith.

Religious beliefs should play a role in our public life, especially when it comes to great moral questions, as they have from the abolition movement to the civil rights movement to efforts to advance a culture of life. For the most part, America has achieved the right balance — one that recognizes the importance of faith in our common life while resisting the use of politics to advance sectarian purposes. We believe people of all faiths have every right to be active in politics — but there are no Christian or Hindu parties in America. That is as it ought to be.

And for those of us who are Christian, there is an important context to bear in mind: Jesus’s entire ministry was directed against the pretensions of earthly power, and Christianity is trans-political, beholden to no party and no ideology. The City of Man and the City of God are different, and we should respect and honor those differences.

Mike Huckabee, by all accounts a faithful Christian, may not have crossed any bright lines yet — but he’s edging close to them. He should pull back now, before his political ambitions injure what he claims to care about, and undoubtedly does care about, most.

Peter Wehner, a deputy assistant to President Bush from 2001 to 2007, is a senior fellow at the Ethics and Public Policy Center.