In part their argument is that churches are failing by politicizing the spiritual, mythic, and archetypal role of religion and religious influence in Western culture.
This PBS discussion is worth a read. From Religious Literacy;
ABERNETHY: Prothero thinks churches and families are not teaching religion well, so he wants a course on the Bible for every high school student; also, a course in world religions -- Judaism and Christianity and Islam, Hinduism and Buddhism. Prothero insists requiring such courses would not violate the separation of church and state.
Prof. PROTHERO: There's a distinction between preaching religion and teaching about religion. You can't be telling kids, accept Jesus as your Savior and Lord. That's absolutely, totally unconstitutional. Now the other thing, talking about religion, teaching about religion, is totally constitutional. There's no debate about this.
ABERNETHY: But there is debate. Critics say Christianity and Judaism would be favored over other religions in a required course on the Bible, and that would not be neutral. Barry Lynn heads Americans United for Separation of Church and State.
Reverend BARRY LYNN (Americans United for Separation of Church and State): Court decisions make it clear that we can't prefer some religions over others or prefer all religion over no religion. I think that when you take one holy scripture -- the holy Christian Bible -- and decide to use that as the centerpiece for your class, as Stephen Prothero suggests, you're on very shaky constitutional ground.
ABERNETHY: Charles Haynes of the Freedom Forum agrees.
Dr. CHARLES HAYNES (Senior Scholar, Freedom Forum First Amendment Center): I think a required Bible course is not a good idea. I think it would be giving too much room in the curriculum to one scripture and some faiths and not others. But, on the other hand, I think a required world religions course would be a good idea, because there I think we expose students to a wide variety of beliefs and practices.
ABERNETHY: When the Supreme Court ruled out school-sponsored prayer in 1962, it set off a generation of conflict not only about school prayer but also about teaching religion. Were the justices really against it?
Dr. HAYNES: They were heard somehow as though telling public schools to ignore religion, to leave it out. But that was a deep misunderstanding of those decisions. They were saying that the state may not impose religion or sponsor religion, but of course public schools must teach about religion in order to offer a good education.
ABERNETHY: At first, after the prayer decision some school districts avoided controversy by ignoring religion altogether. Then, partly because of explanations by the Freedom Forum of how to teach about religion, there was what Haynes calls a "sea change."
Dr. HAYNES: There's probably more religion in our public school curriculum today than there has been at any time since the 19th century. It's across the country in social studies courses particularly.