Invoking the memory of George Washington, the mission of a church, and the future of southern Prince George's, the parishioners of the county's oldest church pleaded for two hours with planning board members yesterday to block a proposed roller skating rink and bowling alley a quarter of a mile away.

The parishioners, of St. John's Episcopal Church, founded in 1692 on Broad Creek in Oxon Hill, said the proposed development would aggravate flooding problems that have plagued their property for years. But planning board members, after hearing two hours of emotional testimony, split 2-2 over whether to give the developer the commercial zoning he requested or to leave the area zoned for houses on half-acre lots. Their failure to agree left intact a staff recommendation to allow the developer to proceed with restrictions.

The County Council has yet to give its required final approval, which the developer has been seeking since 1975.

Developer Lynn Johnson of Oxon Hill had nothing to say. "After 19 public hearings, I have no comment."

"It's a very important issue, a very emotional issue, and I don't want to make any personal statements about anyone," said the Rev. John Baldwin, current rector of St. John's, following the vote. He added shortly afterwards, "She board member Ann Shoch, who voted for the development is just pro-development down the line. It's outrageous; she just has blinders on."

Shoch said at the hearing she feels there are too few employemnt opportunities in the area.

The current controversy centers on a 15-acre tract at the apex of Oxon Hill and Livingston roads in Oxon Hill, across from a shopping center. Johnson applied for commercial zoning for the heavily wooded tract in 1975 but was turned down by the planning board. He applied again in 1979 to develop seven acres of the property. The planning staff recommended against it but the five-member board agreed to grant Johnson's request.

The council refused to make a final decision, saying that a a formal, large-scale review of the area's zoning would soon be under way and individual cases should wait. But Johnson became impatient with the extended wait for the review, which still has not occurred, and sought a decision.

Russell Shipley, Johnson's attorney, said commercial zoning is in accord with the master plan for the area and that parishioners' concerns about flooding are unfounded. Planning board staffers agreed, and even the church's attorney said he had no evidence to support his claim that the development would cause flooding and traffic problems.

But for the parishioners and supporters of St. John's, the issue goes much deeper. "It would just be so incompatible with this area," said Helen O'Leary, who has researched the church's history, "It's pretty well established that George Washington used to come across to St. John's for services."

St. John's is said to be the oldest church site and the oldest parish in the county. The first building was replaced in 1766 with the Georgian structure that stands today. Parishioners said they fear the impact of changing times.

As it is, Baldwin said the church parking lot is used, "to be blunt, as a lovers lane," and the rink would attract more teen-agers. Parishioner James Titus asked the board to consider the effect on the graveyard, which also floods. "Consider that in the next century, the sea level is expected to rise up to a foot," he said. "Needless to say, we take a long perspective."