NASHVILLE, Tennessee (AP) — Some U.S. churches concerned they could be sued by gay couples, are changing their bylaws to reflect their view that the Bible allows only marriage between one man and one woman.

Although there have been lawsuits against wedding industry businesses that refuse to serve gay couples, attorneys promoting the bylaw changes say they don’t know of any lawsuits against churches. Critics say the changes are unnecessary, but some churches fear that it’s only a matter of time before one of them is sued.

Gay Christian Network executive director Justin Lee, who supports such ceremonies, says the First Amendment protects churches from being required to hold them.

Some Christian denominations, such as the United Church of Christ, accept gay marriage. But the majority of Christian denominations view homosexual relationships as sinful.

Thirteen states and the District of Columbia now recognize gay marriage.