Eric Rassbach is an attorney with the Becket Fund for Religious Liberty, a public interest legal group that defends the free expression rights of all faiths. He said it is unlikely the government would try to force a pastor to perform a same-sex marriage, but churches that rent out their facilities to the general public could face problems if they refuse to rent to gay couples.
Although his organization has not advocated it, he said it could strengthen a church's legal position to adopt a statement explaining its beliefs about marriage.
"A number of groups don't have a written doctrine," Rassbach said. "Say a group like the Primitive Baptists — they don't want a written-down credo, but the courts like written-down things."
Rassbach said it was important for churches to get their beliefs in writing before a dispute arises, otherwise it can look to a court as if something was done after the fact as an attempt to cover up hostility to gays.
Airline Baptist Church Senior Pastor Chad Mills said members of the public use their facilities in Bossier City, La., for many activities, including Zumba classes. In the past, anyone who could pay the fee was allowed to reserve the space. But recently, the church changed its rental policy to allow wedding-related events only for male-female couples.
Some denominations are less concerned about the Supreme Court rulings. The Assemblies of God, the group of churches comprising the world's largest Pentecostal denomination, sought legal advice after the rulings. An attorney for the group distributed a memo to ministers saying there was no reason to change their bylaws.
However, the memo also said that "doing so is not inappropriate, and may be warranted based on future rulings by the Supreme Court and other state and federal courts."
The bylaw changes are coming at a time when many churches are wrestling with gay marriage in general and are working hard to be more welcoming to gays and lesbians.
"It's probably one of the most difficult issues our churches are facing right now," said Doug Anderson, a national coordinator with the evangelical Vineyard Church. "It's almost an impossible situation to reconcile what's going on in our culture, and our whole theology of welcoming and loving people, versus what it says in the Bible."