President-elect Barack Obama is taking a lot of heat for selecting the Rev. Rick Warren, an ardent opponent of abortion rights and same-sex marriage, to give the inaugural invocation next month. Obama differs with the evangelical preacher on abortion and many other social issues, but he did not let those differences prevent him from extending the invitation.

It was a courageous decision. It was also the correct one.

Of all the tests Americans take each year, it's time to throw out the most narrow-minded kind: the litmus test. The left and right are equally guilty of administering these political pass/fail quizzes.

For example: I oppose same-sex marriage. When I said so in a column distributed primarily to African American newspapers, I received more than 200 e-mails attacking my position, many of them part of an orchestrated response.

Of course, the dissenters had a right to express their opinions, just as I had expressed mine. And that's the point: We can and do have different points of view. But we shouldn't demonize opponents simply because they don't share our opinions.

Associating only with those who share your opinions gives you a rubber stamp, but few opportunities for personal growth. Moreover, it prevents people who disagree from engaging each other on issues where they may have common ground.

I speak from experience. During the late '80s, I appeared as a regular panelist on a Howard University talk show along with Larry Wade, a columnist and editorial writer for the Washington Times. Larry was to the right of Rush Limbaugh, which guaranteed that he and I would clash on virtually every social issue.

But Larry and I would often go out for drinks after each show, and during those conversations we discovered that we genuinely liked each other. And I learned that, contrary to my initial impression, Larry was not just spouting the party line; he really believed what he was saying.

After suffering from a brain tumor, Larry died in 1990, at the age of 41. We had become such good friends by then that his wife, Deborah Burstion-Wade, who worked in the Reagan administration, asked me to speak at his funeral. And I did. Larry was more than a black conservative; he was my friend.

I also developed a close friendship with another conservative, Nat Irvin II, whom I met while serving as editor of Emerge magazine. We have spent nights in each other's homes, and we try to get together every Christmas, when I visit my mother in Augusta, Ga., and he visits his parents in North Augusta, S.C. When I had a bypass operation, Nat's father called to pray with me, and I later coached him through a similar operation.

The younger Nat is a university professor, and we talk about education more than we discuss politics. He is also a futurist, so we talk about global trends that have absolutely nothing to do with race. When the two of us speak on the phone or in person, any subject can come up.

If Rick Warren and his critics met away from the glare of the media, I suspect that they, too, would find they share many beliefs in common, despite their differences.

In an interview with ABC News, Warren said, "I'm a pastor, not a politician. People say, 'Rick, are you right-wing or left-wing?' I say, 'I'm for the whole bird.'"

But critics have focused on other comments by Warren, an outspoken supporter of Proposition 8, the ban on gay marriage recently approved in California. In an interview with Beliefnet, Warren said, "I have many gay friends. I've eaten dinner in gay homes. No church has probably done more for people with AIDS than [Warren's] Saddleback Church."

Later in the interview, however, Warren compared the campaign to redefine marriage to legitimizing incest, child abuse and polygamy. And that's what most upset Warren's critics.