The Presbyterian Church\'s 220th General Assembly in Pittsburgh from June 30-July 7 will debate the divisive issues of gay clergy, which many in the church thought had been settled, and same-sex marriage.

Last year, a majority of presbyteries ratified the Presbyterian Church's 2010 General Assembly approval of ordaining non-celibate gay clergy.

But that didn't settle the issue.

Opponents of ordaining gay clergy will try to undo the change at this year's biennial assembly that meets in Pittsburgh from June 30-July 7.

The church's new language sidesteps the issue of sexuality and specifies that ordination standards should “reflect the church’s desire to submit joyfully to the Lordship of Jesus Christ in all aspects of life,” the Religion News Service reports. Regional presbyteries, which preside over ordinations, are only required to base decisions on common questions asked of all candidates.

Opponents will try to restore the 1996 standard that required “fidelity in the covenant of marriage between a man and a woman or chastity in singleness” for all clergy.

Same-sex ordinations and marriage have been divisive issues for the 2 million-member Presbyterian Church (USA).

The Christian Post reported that dozens of congregations have left the Presbyterian Church after it approved gay ordination last year. And the flight from the faith could continue if the assembly approves a modification to the church's constitution to define marriage as a union of two people. The current definition is "a civil contract between a woman and a man.”

"The marriage issue, depending how the vote goes, has the potential to be very, very distressing to some of our congregations," said the Rev. Sheldon Sorge, pastor in the Pittsburgh Presbytery. "It would not surprise me at all if some congregations would see (approval of same-sex relationships) as the straw that broke the camel's back, for them to leave the denomination."

But a growing number of Presbyterians are accepting of same-sex marriage.

The Huffington Post cited a church survey in February that found 51 percent of church members opposed same-sex marriage, while 34 percent approved, and the remainder were undecided. Among pastors, 41 percent approved of same-sex marriage, while 41 percent were against it. A similar survey in 2005 found just 13 percent of members and 35 percent of pastors favored same-sex marriage.