A Catholic social-services agency urged the Supreme Court this week to rule that the agency can participate in the city of Philadelphia’s foster-care program while refusing to work with same-sex couples. The court should reject the agency’s appeal and make it clear that religious freedom may not be used as a license to discriminate.

Catholic Social Services, which long has participated in Philadelphia’s foster care program, lost its contract to screen prospective foster parents after city officials learned that the agency wouldn’t consider same-sex couples as foster parents. Because that policy is based on the Catholic Church’s teaching that marriage is between a man and a woman, the agency claims that the city is violating its religious freedom.

The agency, joined by two foster parents, also is urging the court to reconsider a 1990 decision that held that the 1st Amendment’s protection of the free exercise of religion didn’t allow believers to opt out of generally applicable laws. A federal appeals court cited that decision in ruling against Catholic Social Services, finding that the city’s enforcement of an anti-discrimination ordinance didn’t target Catholic Social Services for its religious beliefs.

The Supreme Court should affirm the appeals court’s ruling.

Catholic Social Services is a sympathetic plaintiff because of the good work it does for vulnerable children. It’s also true that religious freedom is an important constitutional value, one that in some situations allows religious bodies to engage in discrimination that would be illegal in the larger society.

No one, for example, would seriously suggest that the Catholic Church is required to ordain women as priests because of laws against sex discrimination. The court also has ruled that the 1st Amendment grants religious organizations autonomy in choosing its leaders, including some teachers at church-run schools — even to the point of being immune to lawsuits alleging employment discrimination.

But this isn’t a case about how a religious enterprise organizes itself. Catholic Social Services was screening potential foster parents under a contract with the city. The agency also received a payment for every child the city placed in one of the agency’s affiliated foster homes.

During Wednesday’s oral argument, Justice Brett M. Kavanaugh seemed to be pressing for a compromise ruling. He said that “this case requires us to think about the balance between two very important rights recognized by this court, the religious exercise and belief right, obviously, in the 1st Amendment, and the same-sex marriage right” affirmed by the court in a 2015 decision.

Kavanaugh also noted that Philadelphia contracts with about 30 agencies to identify prospective foster parents and that Catholic Social Services, although it doesn’t work with same-sex couples, is willing to refer such couples to other agencies. He suggested that the court should arrive at a “win-win” accommodation.

That’s a beguiling idea, but it doesn’t deal with the problem of a city contractor engaging in illegal discrimination. And what if a religious agency, citing its beliefs, refused to work with interracial couples? That scenario was raised by several justices, including the newest member of the court, Amy Coney Barrett.

A lawyer for the U.S. Justice Department, which is supporting Catholic Social Services, suggested that situation might be different because “this court has made clear repeatedly that there’s a particularly compelling interest in eradicating racial discrimination.” A lawyer for the agency made a similar comment.

The court has said that eradicating racial discrimination is vital, but it also has also emphasized the importance of combating sex discrimination. That includes discrimination on the basis of sexual orientation, as the court ruled in a landmark decision in June. A ruling for Catholic Social Services would weaken that protection and undermine the court’s ruling on marriage equality.

A decision allowing Catholic Social Services — or any other government contractor, religious or otherwise — to engage in discrimination against same-sex couples would not be a “win-win” ruling. It would represent a grievous loss for the cause of equality for gay and lesbian Americans that the court has done so much to advance.

This story originally appeared in Los Angeles Times.