(RNS) Presbyterians who support gay rights are prepping sanctuaries this Sunday (July 10) to celebrate the passage of a new church policy that allows gay pastors to serve openly for the first time in the denomination's history.

As the new policy for the Presbyterian Church (USA) becomes official that day, several left-leaning churches "will mark the moment with prayer and rejoicing" in their Sunday services, according to a press release from More Light Presbyterians, which advocates for gay rights in the church.

"The Presbyterian Church enters a new era of equality on Sunday," said Michael Adee, the group's executive director. "It is a historic moment. It returns us to ordination standards that focus on faith and character rather than one's marital status or sexual orientation."

The new policy removes language from the denomination's constitution that had barred homosexuals from serving as church ministers, elders and deacons. It allows each presbytery - or regional governing body - to decide what sexual standards to place on ordination.

The resolution, which had failed in different forms in recent years, needed approval from both the PC(USA) General Assembly as well as from presbyteries; 97 of the denomination's 173 presbyteries voted to approve the new policy.

But despite Sunday's celebrations, gay ordination remains a contentious issue for many within the church.

"In passing (the policy), the denomination removed all sexual behavior standards from its constitution," said the Rev. Parker T. Williamson, editor emeritus of the conservative publication The Layman, which actively opposed the change. "Scripture is very clear that there are standards relating to our sexual behavior ... but this denomination has decided it doesn't have any standards."