By Bill Mears, CNN Supreme Court Producer

(CNN)– Linda Stephens has lived in her upstate New York community for more than three decades and has long been active in civic affairs.

But as an atheist, those views have put her at the center of a personal, political, and legal fight that has reached the U.S. Supreme Court.

The issue is public prayer at her local town board meetings, another contentious case over the intersection of faith and the civic arena.

The justices on Wednesday will hear arguments over whether Greece, New York, may continue sponsoring what it calls "inclusive" prayers at its open sessions, on government property.

Stephens and co-plaintiff Susan Galloway have challenged the policy, saying virtually all of those invited to offer legislative prayers over the years were Christians.

"It's very divisive when you bring government into religion," Stephens told CNN from her home.

"I don't believe in God, and Susan is Jewish, so to hear these ministers talk about Jesus and even have some of them who personally question our motives, it's just not appropriate."

The town of about 94,000 residents counters that after concerns from the two women and others, it sought diverse voices, including a Wiccan priestess, to offer invocations. Officials say they do not review the content of the remarks, nor censor any language.

"The faith of the prayer giver does not matter at all," said John Auberger, Greece's board supervisor, who began the practice shortly after taking office 1998. "We accept anyone who wants to come in and volunteer to give the prayer to open up our town meetings."

A federal appeals court in New York found the board's policy to be an unconstitutional violation of the Constitution's Establishment Clause, which forbids any government "endorsement" of religion.

Those judges said it had the effect of "affiliating the town with Christianity."

"To the extent that the state cannot make demands regarding the content of legislative prayers," said Judge Guido Calabresi, "municipalities have few means to forestall the prayer-giver who cannot resist the urge to proselytize. These difficulties may well prompt municipalities to pause and think carefully before adopting legislative prayer, but they are not grounds on which to preclude its practice."

Some legal experts say while the high court has allowed public prayers in general, it has not set boundaries on when they might become too sectarian in nature.

"The case involves a test between two different kinds of legal rules," said Thomas Goldstein, SCOTUSblog.com publisher and a leading Washington attorney.

"The Supreme Court has broadly approved legislative prayer without asking too many questions. But in other cases where the government is involved with religion, it has looked at lots of different circumstances. So we just don't know whether this court will be completely approving of legislative prayers in this instance."

The justices are now being asked to offer more firm guidelines over when and if such public prayers are constitutionally acceptable.

Felt marginalized

Galloway and Stephens say the elected board of the community outside Rochester almost always invited Christian clergy to open the meetings, usually with sectarian prayers. And they say they felt "marginalized" by the practice.

"When we tried to speak with the town, we were told basically if we didn't like the prayers, we didn't have to listen," said Stephens, "or could stand out in the hallway while they were going on."

Americans United for Separation of Church and State, the Washington-based group that is representing the two women, cited records showing that between 1999 and 2010, approximately two-thirds of the invocations contained the words "Jesus Christ," Jesus," Holy Spirit," or "Your Son."

And the lawsuit claims that from 1999 through 2007, every meeting had a Christian-only invocation. Following the complaints from the plaintiffs, four other faiths were invited in 2008, including a Baha'i leader and a Jewish lay person.

The plaintiffs say the Christian-only invocations resumed from January 2009 through June 2010. They claim those invited to the monthly meetings were selected by a city employee from a local guide that had no non-Christian faiths listed.

"Politics and religion simply don't mix, and they certainly don't mix in the local context of the Greece town council," said the Rev. Barry Lynn, AUSCS executive director.

"The town seems to take the position that because once or twice over a decade, it hears from someone of a different religion, that somehow is inclusive. It trivializes what's going here - a local government that should be willing and interested in participation of all its citizens, it wants those citizens to participate in an almost inevitably Christian prayer, in order to begin doing their business."

Different rulings

While the 2nd Circuit U.S. Court of Appeals in New York last year unanimously ruled against Greece's policy, other courts around the country have found such invocations - if inclusive and limited in scope - to be permissible.

Congress regularly opens its sessions with a prayer. Wednesday's invocation by House Chaplain the Rev. Patrick Conroy began: "Eternal God, we give you thanks for giving us another day. Once again, we come to ask wisdom, patience, peace, and understanding for the members of this people's House."

Nearly 120 members of Congress, mostly Republicans, along with several state attorneys general have filed supporting legal briefs backing the city. So has the Obama administration.

"The history of prayers offered in connection with legislative deliberation in this country makes clear that a legislative body need not affirmatively solicit a court-mandated variety of different religious faiths– from inside and outside the borders governed by the legislative body– in order to avoid running afoul of the Establishment Clause," said Justice Department lawyers' in their amicus brief.

The Alliance Defending Freedom, a legal ministry based in Scottsdale, Arizona, filed the lawsuit on behalf of the Greece Town Board, saying the Supreme Court has upheld the practice of government bodies "to acknowledge America's religious heritage and invoke divine guidance and blessings upon their work."

"A few people should not be able to extinguish the traditions of our nation merely because they heard something they didn't like," said Brett Harvey, an attorney for the group. "Because the authors of the Constitution invoked God's blessing on public proceedings, this tradition shouldn't suddenly be deemed unconstitutional."

Stephens realizes the stakes are high for her community and for the law as a whole. But on a personal level, this legal fight has been tough.

"I've received something of a backlash, both Susan and me," the retired librarian said. "Threatening letters, some vandalism to my property, things like that. The prayers, and all the controversy, it makes you feel like an outcast, like we don't count in our town."

The case is Town of Greece, N.Y. v. Galloway (12-696). A ruling is expected by early summer.