Last week I finally started reading a slim volume that’s been waiting on my bookshelf since last fall. Not a moment too soon.

A Public Faith by Miroslav Volf (Brazos Press, 2011) tackles a chronic, nettlesome question: What kind of relationship should Christians (and perhaps by extension, other people of faith) have with their culture?

Writing “as a Christian theologian to followers of Christ,” Volf offers an alternative approach to the extreme positions that can define the boundaries of faith in the public square: “totalitarian saturation of public life with a single religion” or “secular exclusion of all religions from public life.” (He might have added an older reflex among many Christians, to vacate and try to ignore the public square altogether.)

The timing was good because, along with the rest of the universe, I was trying to digest President Obama’s endorsement of same-sex marriage, which came on the heels of the North Carolina amendment that banned such unions in the state.

But that was only the biggest headline among several in recent weeks that reminded me how hard it is to navigate a believer’s “dual citizenship.” Michelle Bachmann’s recent Swissues are nothing compared to the complications of being a Christian and an American.

For starters, there was military college course, now suspended, that advocated total war on Islam, using the World War II firebombing at Dresden and the nuclear attacks on Hiroshima and Nagasaki as models for how to deal with Muslim sites.

There was a budget proposal in the U.S. House that would have reduced the deficit by drawing down education, welfare and other social-aid programs, while increasing defense spending and not touching tax rates. (The Senate voted down this budget on May 16.)

Closer to home, several readers didn’t like a piece I wrote in a Christian magazine, which reported on a survey that found that Fox News viewers were not as well informed about the Occupy Movement as consumers of other news outlets and that Fox viewers have a significantly more negative view of the Occupy protesters.

I’m not surprised by criticism. But one reader baffled me when he said he didn’t want to believe that “a professor of communications from the restoration side could believe that swill.” (He was referring to my church heritage and that of the college where I teach, which has its roots in the Stone-Campbell, or “Restoration,” Movement.) His remark left me wondering: When did uncritically accepting Fox News—or any media outlet—become an essential of the faith?

I can spot a thread running through these events: some American values and ideas—including good ones—are not necessarily Christian ones.

What I mean is that as an American, I cherish free speech, equal rights under law, freedom of religion and a long list of other civic virtues. But as a Christian, I have other principles besides, expressed most obviously in Sermon on the Mount and modeled most powerfully by Jesus himself.

No doubt that American and Christian values peacefully co-exist much of the time; sometimes they even agree.

But not always. As the last few weeks show, there’s often tension if not contradiction or outright conflict. For instance, I can’t see how to honestly interpret Jesus’ words or life as condoning “total war” against people of other faiths.

And maybe I’m missing something, but the thrust of that proposed budget seemed to turn upside down those Scriptures that warn against God’s people relying on chariots for their security, as well as dozens of texts that call for generosity and justice for poor people (Isaiah 1:17, 10:1-2; 25:4; 47:6; 58:7; Proverbs 14:21, 31; 19:17; 21:13; 22:9; 28:27; 31:8-9—just for starters).

Then there’s same-sex marriage. As an American, I believe in equal rights under law for all people, including gays and lesbians.

On the other hand, same-sex marriage is not biblical. We can debate whether all those Jewish and Christian Scriptures that govern sexual conduct are relevant or binding or even rightly interpreted, but four millennia of teaching and tradition places the burden of proof on those who say same-sex unions should be consecrated by the church.

To put it another way: While same-sex marriage may be American, a matter of equal rights and social order, I can’t say it’s Christian.

I find Volf helpful when thinking through these kinds of tensions, in large part because he starts by recognizing there’s no single way in which Christian faith ought to relate to culture as a whole. “The relation between faith and culture is too complex for that,” he writes. “Faith stands in opposition to some elements of culture and is detached from others. In some aspects faith is identical with elements of culture, and it seeks to transform in diverse ways yet many more.”

Volf uses his book to answer three “simple questions”:

1.  In what ways does the Christian faith malfunction in the contemporary world, and how should we counter these malfunctions?
2.  What should be the main concern of Christ’s followers when it comes to living well in the world today?
3.  How should Christ’s followers go about realizing their vision of living well in today’s world in relation to other faiths and together with diverse people with whom they live under the roof of a single state?

I’m not sure they’re actually that simple, but if you’re interested in thoughtful answers to these questions, pick up this book. Volf is accessible—a fine, formal and clear writer who keeps the theological jargon tamped down. He’s helping me think about the tension I’ve been feeling, as keenly as ever, of living as a Christian in America.