WASHINGTON, March 19 (RNS) -- It's back to the drawing board for the Presbyterian Church (USA).When the 2.5 million-member church met last summer in Long Beach,Calif., delegates approved a ban on same-sex unions by only 17 votes andsent it to 173 regional presbyteries for approval to be added to thechurch's constitution.

At the time, conservatives said the presbyteries were far lessdivided on the issue than the voting delegates and promised the measurewould pass by a large margin. Liberals said they would aggressivelylobby to defeat it.

When the 87th presbytery voted against the so-called ``Amendment O''on March 14, the measure was effectively killed and the church now findsitself in exactly the same place it was a year ago, with the issue stillunresolved.

In this round, the liberals have come out on top.

``We were really on a roll, and this is a defeat, but we have to seethis as one defeat in a very large war,'' said the Rev. ParkerWilliamson, a leader of the church's conservative wing.

In many ways, the Presbyterian Church has become a barometer of howgay issues are playing out in U.S. churches. The back-and-forthdecisions reveal a seeming inability to find a permanent resolution.

Because Presbyterians meet annually, the issue never quite seems togo away. Issues left unresolved at one meeting inevitably return thenext year. So when the church meets in June in Louisville, Ky., the gayissue will dominate the agenda - again.

Both conservatives and liberals concede the ban failed because itwas so vague that presbyteries were unsure what it would ultimatelymean. It did not explicitly ban same-sex unions, but rather ``anyceremony or event'' which blesses a relationship other than heterosexualmarriage.

Opponents said it could keep ministers from officiating at a gayperson's funeral, or giving communion to gay church members, andultimately would tie the hands of local clergy in ministering to theirflock.

This is the second time Presbyterians have rejected a ban onsame-sex unions; a similar vote failed in the presbyteries in 1995.After a church court ruling last year, ministers are free to conductservices joining gays in same-sex ``unions'' as long as they are notexplicitly equated with ``marriage.''

Time is running out for a similar ban proposal to emerge from thepresbyteries to be considered by the next General Assembly meeting. Mostexpect the June 9-16 meeting to revolve instead around the issue of gayordination, with progressives hoping to remove a five-year-old ban ongay clergy.

It is unclear how the defeat of the same-sex union ban will affectthe debate on gay ordination. Some say the church is so tired ofwrestling with the issue that delegates may be reluctant to try to dealwith it legislatively.

But what is crystal clear is that the nation's largest Presbyterianbody is deadlocked on how - of if - they can move beyond the debate. ``From a human perspective, there is no solution on the horizon, andI don't think either side is willing to say, `Let's agree todisagree,''' said the Rev. Joe Rightmyer, director of the conservativePresbyterians for Renewal. ``We're in need of divine intervention. Nohuman solutions have been offered that would bridge the impasse overthis issue.''

If anything, the defeat of Amendment O shows that the gay issue isnot solely about gays. Conservatives maintain the issue is really aboutbiblical authority, and say ignoring biblical prohibitions againsthomosexuality would downplay the importance of Scripture.

Liberals, meanwhile, say the issue is about human relationships andGod's care for all his creation, gay and straight. They also saywhatever the church ultimately decides will speak volumes about thePresbyterian tradition of allowing churches and pastors to make theirown decisions on ministry.

The Covenant Network of Presbyterians, a liberal group which opposedAmendment O, says attempts to legislate the issue on the national levelwill never work.

``My hope is that moderate conservatives and moderate liberals aregoing to stand up and say, both to the left and the right, that we'retired of this war,'' said the Rev. Laird Stuart, pastor of CalvaryPresbyterian Church in San Francisco and co-moderator of the CovenantNetwork. ``This is not an essential, this prohibition does not belong inour life together, so let's leave it up to the (churches) andpresbyteries and move on.''