Prior to the legalization of gay marriage, gay activists said that under no circumstances would an affirmative ruling from the U.S. Supreme Court on this issue result in a diminution of religious liberty. They were either wrong or they lied. No matter, no one now disputes that there is a determined effort to use gay rights as a club to smash the religious liberty protections afforded by the First Amendment.

Kate Drumgoogle was fired from Paramus Catholic High School in New Jersey last January after school authorities learned that she violated her contractual obligations. Now she is suing the school, the principal, and the Archdiocese of Newark claiming victim status; a judge has ruled that the case can move forward, denying a request to dismiss it. Drumgoogle was given the opportunity to resign, but she refused. The case has received nationwide attention, and that's because Drumgoogle is "married" to another woman, Jaclyn Vanore.

Drumgoogle was a guidance counselor and a basketball coach. When she took the job, she never disclosed her marital status, yet she agreed to abide by the school's Ministerial Policies and the Code of Ethics; they require adherence to Catholic teachings, among them being the stipulation that marriage is the union of one man and one woman.

No one knew of Drumgoogle's gay marriage until the sister of the woman she claims to be married to posted the information on social media. Elaine Vanore sent pictures of the ceremony to the Paramus Catholic Facebook page, the school's alumni page, and the page of school president James P. Vail. She did so following an argument she had with her sister, Jaclyn, the "wife" of Drumgoogle.

This case is not an anomaly. Dozens of lawsuits have been filed by gay employees against their Catholic employer, all alleging discrimination. The real issue here is that these gays have purposely violated their contract—an agreement to which they voluntarily consented—though no one would know this by following media accounts of these disputes. They have turned this into a persecution campaign by the Catholic Church.

It's not just gay activists who are trespassing on the religious liberty prerogatives of Catholic schools—the Obama administration is doing the same. Last year, the Equal Employment Opportunity Commission filed a complaint against a Georgia Catholic academy because it fired a gay teacher who planned to marry his boyfriend.

Every time something like this happens, we hear how indefensible it is to discriminate against gays as it is blacks. The conventional wisdom does not take into consideration a critically important difference: homosexuality, as opposed to the status of being a homosexual, is the issue; there is no analogue with race.

Gay teachers in Catholic schools are not being driven out because they are gay: they are being dismissed because they publicly flout Catholic teachings on the subjects of sexuality and marriage, and because they violated their contractual responsibilities.

Following the Bible, the Catholic Church rejects homosexuality; it also holds that marriage is a monogamous institution between a man and a woman. And just like secular institutions, it expects that the terms of its employment contracts should be honored.

The big mistake is conflating behavior (homosexuality) with an ascribed status (race): Behavior is an achieved status having nothing to do with a fixed status. As with all behaviors, homosexuality is subject to moral approval or disapproval. These judgments take on greater weight when they are grounded in Judeo-Christian precepts, the very foundation of the United States.

It should be further noted that the Catholic Church rejects "unjust discrimination," thereby acknowledging situations where just distinctions are warranted. So, too, does the larger society: there are many laws that treat people differently based on age (driving and voting), veteran status, handicapped conditions, and the like. The private sector does the same, as evidenced by height requirements for certain rides at amusement parks and "ladies night" privileges at pubs.

Regardless of how one feels about these matters, there is one overriding concern that should be controlling: the First Amendment right to the free exercise of religion.

Bill Donohue is President and CEO of the Catholic League for Religious and Civil Rights, the nation's largest Catholic civil rights organization. He was awarded his Ph.D. in sociology from New York University and is the author of seven books and many articles.