When the stream of white smoke billowed from the smokestack above the Sistine Chapel on Wednesday, there was rejoicing by Catholics in the streets of Rome, and around the world that Jorge Mario Bergoglio, archbishop of Buenos Aires, was elected Pope.

I wish I could say the same was true among all my fellow evangelicals. Earlier this week, I wrote an email to supporters encouraging them to pray for Catholics and their leaders as they select the next pope. My note prompted several derisive emails from evangelicals, who make up the majority of my support network.

One e-mailer responded in a way that I think exemplifies the view of too many evangelicals. He advised me not to "minimize" the doctrinal differences between Catholics and evangelicals. And he accused me of "blurring" the lines between evangelicals and Catholics and of advocating for a "one-world religion."

Thankfully, most evangelicals wouldn't be that uncharitable toward our Catholic brothers and sisters. But, sadly, a minority would endorse that characterization. They need to realize that they, too, have a stake in who is elected pope, because without a strong pope, evangelicals will lose their best allies in the most important cultural and political battles of our age.

Catholics and evangelicals (and to a lesser extent orthodox Jews and Mormons) have formed a formidable partnership in recent decades against the threats of secularism, relativism and Islamism.

As an evangelical, I was delighted that the last two popes were moral and theological giants. Together, John Paul II and Benedict XVI gained many evangelical admirers by preaching against the "culture of death" and the "dictatorship of relativism" and for a "culture of life."

And, as Catholic theologian George Weigel argues in his new book Evangelical Catholicism, John Paul II and Benedict XVI introduced a new "evangelical" period for the Catholic Church -- an era in which the Catholic Church offered a confident rebuttal to the false promises of the secular world.

I don't mean to downplay the real and significant theological differences between our two faiths. But Catholics and evangelicals need to remain allied, and in solidarity, against the increasingly aggressive secularism of our age.