A group of Christians, including a former atheist and a philosopher, have launched a new campaign that calls fellow believers to "pray for an atheist" beginning with April Fools' Day.

"We want you to select an atheist friend or relative and pray for them by name each day during the month of April, 2010 (and beyond!). It’s easy and could make an eternal difference for someone you love," the campaign states on its Facebook page.

Currently, "Pray for an Atheist" is purely a Facebook initiative and is designed to not only encourage Christians to pray for nonbelievers but also to become better equipped to share their faith in a respectful manner with atheists.

A number of atheists have expressed their strong objections to the idea of Christians praying for them, according to James S. Spiegel, author of The Making of an Atheist.

"I personally find it offensive if anybody wants to pray for me," Spiegel cited one as saying.

Other more profane and vulgar comments have been deleted.

Spiegel believes "all of this vitriol" confirms the thesis of his book, which explores the moral-psychological roots of atheism.

"Atheism is not at all a consequence of intellectual doubts," stated Spiegel, professor of philosophy and religion at Taylor University in Upland, Ind. "These are mere symptoms of the root cause – moral rebellion. For the atheist, the missing ingredient is not evidence but obedience."

The Taylor professor contends in his book that the atheist's argument of unbelief because of the existence of evil or lack of scientific evidence is only a smoke screen to mask the real issue, which is personal rebellion.

"The rejection of God is a matter of will, not of intellect," he argues in his recently released book.

"In short, it is sin that is the mother or unbelief."

Responding to objections from atheists to the prayer campaign, Spiegel said, "Atheists simply have no reason to object to our praying for them, especially since, given our worldview, it is an act of love."

"After all, if God does exist, then it would be an enormous benefit to atheists if they come to believe this," he added. "Therefore, I would ask atheists to respect my right to do what I want in the privacy of my own home, as I kneel in prayer on their behalf."

The prayer campaign was started by Spiegel and Holly Ordway, author of Not God's Type and a former atheist. It comes as atheists are scheduled to converge in New York this weekend for the 36th National Convention of American Atheists.

The national organization claims there are 30 million atheists in the U.S. According to the 2008 American Religious Identification Survey, meanwhile, the number of outright atheists was estimated at 1.6 million but the population is growing.