By Matt Stroud

PITTSBURGH (Reuters) - The U.S. Presbyterian Church on Friday narrowly rejected a proposal by same-sex marriage proponents for a constitutional change that would redefine marriage as a union between "two people," rather than between a woman and a man.

The 338-308 vote followed nearly four hours of heated debate at the Church's General Assembly in Pittsburgh, a biennial gathering to review policy.

The Church, with around 2 million members, currently allows ministers to bless gay unions but prohibits them from solemnizing homosexual civil marriages.

Opponents of the change argued the move would alienate the Church from Presbyterian churches in other countries, while backers said it should be a leader in advocating for the acceptance of same-sex marriage.

Michael Wilson, of Lancaster, Pennsylvania, told the General Assembly the proposal threatened to "tear the Church apart."

But Piper Madison, from North Alabama Presbytery, said "the Church doesn't ask us to do what others approve of, it asks us to do what is right."

A compromise proposal that would have changed the Church's interpretation of the Book of Order - it's constitution - while leaving the marriage language intact, was rejected by a vote of 397-266.

Following the session, Neal Presa, a pastor at Middlesex Presbyterian Church in New Jersey who moderated the General Assembly debate, brought the congregation together in prayer.

"Some of us weep while some of us rejoice," he said, bowing his head. "We are a divided church."

On Thursday night, the Church's Civil Union and Marriage Issues Committee voted 28-24 in favor of the change.

The legalization of same-sex marriage has created a quandary for some churches in the United States. While gay parishioners have pushed for churches to sanctify their marriages, other parishioners have said marriage should be reserved for heterosexual couples. Continued...