Albert A. Buonanno of Denver had worked at AT&T Broadband for two years. But in a 2001 reorganization, the company directed employees to sign a "certificate of understanding." The document said employees must "fully recognize, respect, and value the differences among all of us," including "sexual orientation."

Buonanno, who attends a Baptist General Conference church, told his supervisor in a letter that he wouldn't discriminate against or harass homosexuals. But he also said he couldn't sign the statement because it contradicted the Bible. Buonanno's supervisor fired him the next day.

The Rutherford Institute, a religious liberties organization based in Charlottesville, Virginia, is representing Buonanno, 47, and a handful of others. They all lost their jobs for refusing to condone employment policies they found biblically immoral.

The culture war over homosexuality in America has moved to a new front—the workplace. Christian observers say millions of employees are being commanded not just to tolerate homosexual behavior but also to respect and even promote it.

"There are certain things you can't say, or joke about, in the name of tolerance," Rutherford Institute founder John W. Whitehead told Christianity Today. "It's not so much the gay groups as much as the big corporations wanting to make sure they are above criticism."

According to the Human Rights Campaign, the largest pro-homosexual political organization in the country, at least 300 of the companies in the Fortune 500 have included sexual orientation in their nondiscrimination policies. Heterosexual employees who balk at such rules are punished, sometimes severely.

In October, the Rutherford Institute filed a federal suit against the Department of the ...