WASHINGTON — A San Francisco campus conflict between religious devotion and human sexuality will now give Justice John Paul Stevens a final opportunity to apply the First Amendment in the 21st century.

Oral arguments this morning will be the first since Stevens announced his retirement from the Supreme Court. More critically, the case involving a Christian student organization at the Hastings College of the Law is the year's most closely watched freedom-of-religion fight.

The first thing lawyers do is fight over what the fight is about.

"It's a skirmish in a long-running battle to create more space to discriminate against gay people," said Paul Smith, an attorney for a gay student group called Hastings Outlaw.

Alternatively, conservatives say the case, Christian Legal Society v. Martinez, is about devout organizations maintaining their integrity and about public institutions not playing favorites.

"Religious groups have a very important purpose in ensuring that members abide by their moral code," said Luke Goodrich, of the Becket Fund for Religious Liberty, a conservative group that says it supports freedom of religious expression. "Groups can't survive if the government can force them to take unwanted members."

Hastings is a public law school, one of several affiliated with the University of California.

The school's students participate in about 60 formally recognized organizations, from the Hastings Association of Muslim Law Students to the Hastings Democratic Caucus. One organization, the Christian Legal Society, draws a particularly bright line for membership.

Students must sign a "statement of faith" to join. The statement recognizes "the Bible as the inspired word of God" and requires officers to "abstain from acts of the sinful nature."

"Unrepentant participation in or advocacy of a sexually immoral lifestyle is inconsistent with an affirmation of the Statement of Faith," a Christian Legal Society resolution states, specifically condemning "all acts of sexual conduct outside of God's design for marriage between one man and one woman, (including) fornication, adultery, and homosexual conduct."

Hastings officials deemed the Christian Legal Society's bylaws a violation of the school's prohibition against discrimination on the basis of religion or sexual orientation. Consequently, the school denied formal recognition to the organization.

Loss of recognition cost the Christian Legal Society a $250 grant. Without official recognition, the society also lacked other benefits, including use of the school's logo, office space and audio-visual equipment. The students consider this discriminatory.

"The ability to participate in a campus forum on equal terms with other groups is the very lifeblood of a student organization," Stanford University law professor Michael McConnell wrote on the Christian Legal Society's behalf.

"Every student group at Hastings has a reasonable choice," attorney Gregory Garre wrote in the law school's brief. "It may either abide by the open-membership policy and qualify for the modest funding and benefits that go along with school recognition, or forgo recognition and do as it wishes."