By law, employers must accommodate reasonable religious expression, but they also must protect against discrimination or harassment, including unwanted proselytizing, said Chris Anders, legislative counsel for the American Civil Liberties Union in Washington who specializes in religion in the workplace.

Coca-Cola, based in Atlanta, and General Motors of Detroit say they do not recognize groups that promote a "particular religion or political belief," saying such groups foster divisiveness.

But Ford allows eight faith-based groups, saying they foster cohesiveness.

Ford initially balked at the idea, fearing some employees would feel excluded if others gathered around a single religion. But three years ago, the company came upon a rather unusual model — allowing faith-based groups to form but requiring them to work together as part of an interfaith network. The network now represents Buddhists, Mormons, Hindus, Jews, Muslims and evangelical Christians, among others.

"It's a great danger many companies and groups will face in the workplace environment," said Joe Lewis, 54, a Jewish representative on the network's board of directors. "If a (manager) likes to have a prayer breakfast and is of a particular faith, others may feel intimidated and excluded.

"Ford, with its commitment to diversity, has found a way around this problem."

The network tries to make sure all faiths feel accommodated — that Muslim workers have a place for foot-washing and prayer, that Christians can punctuate e-mails with a Bible verse or that the proper cake is served to a Jewish employee during Passover.

Federal Home Loan Mortgage Corp., known as Freddie Mac, says it recognizes affinity groups built only around "unchangeable and immutable human differences," such as race, gender or sexuality. The company includes in that definition adoptive parents and military spouses but not religion.

Without formal approval, however, a Christian group meets regularly at Freddie Mac. It is permitted to use empty conference rooms and copiers but does not receive a stipend or hold corporation-wide events.

That reduced status has left Randolph Maxwell and his Christian colleagues feeling like second-class citizens.

"I think it's discriminatory," said Maxwell, 47, director of treasury business operations. He believes his non-Hodgkin's lymphoma was cured miraculously and has committed his life to Christ as a result.

There are enough examples of religious fervor gone awry to give corporations pause.

In February, an American Airlines pilot on a Los Angeles-to-New York flight reportedly alarmed passengers when he asked Christians to raise their hands and called those who didn't raise their hands "crazy."

Several years ago, a Hewlett-Packard Co. employee was fired after posting Bible verses at his cubicle that appeared to condemn gays and lesbians.