Washington — The ''religious'' factor may have less partisan impact in the 1984 national elections in America than in 1976 and 1980. Seven years ago it appeared to help Jimmy Carter; the next time around, it aided Ronald Reagan.
Politicians on the left and right are reportedly urging their church-related constituencies to avoid open confrontation, if possible, over issues such as school prayer, federal aid to parochial schools, and abortion.
At the same time, Washington-based church lobbies are being prodded by their clergies and memberships to broaden their political bases and to respond to diverse views from within.
For example, mainline Protestant churches are being severely chided by some of their own for leaning too far left politically and supporting almost exclusively liberals and Democrats.
And there is evidence that some of the rank and file of the so-called religious right don't support the politically activist role of the Rev. Jerry Falwell of the Moral Majority and other fundamentalist leaders who are pushing a brand of issue-oriented Christianity.
Still uncertain is whether Roman Catholic laymen across the nation will follow the lead of bishops in the United States who have taken a firm stand on nuclear arms and intend to make this a political issue next year. Some observers point out that there are obviously differing views among Catholics on this issue , and that consensus is not likely without direction from Rome.
Meanwhile, despite advice from some of his inner circle to go slow on religious issues, President Reagan is almost certain to intensify his campaign for some type of voluntary school prayer and tax relief for parents whose children attend private and parochial schools.
The President says he believes that the majority of voters favor these things. And, say observers, he sees these issues as a way of not only shoring up his support from religious-right Republicans, but as a vehicle to draw some like-thinking Democrats into his camp.
Meanwhile, liberal-leaning Protestant churchmen are thought to favor former Vice-President Walter F. Mondale - whose father was a preacher and who is seen as a man with deep religious convictions - for the Democratic nomination. Some say Ohio Sen. John Glenn also has strong appeal for many local Protestant churchgoers.
A.James Reichley, a senior fellow of the Brookings Institution and longtime political analyst, warns churches and religious leaders not to overstep their bounds into politics, particularly in areas in which they have little or no expertise. Mr. Reichley, who is just completing a book entitled ''Church and State in the Modern American Democracy,'' scheduled for publication in the fall, says it is proper for churches to bring ''spiritual and moral'' leadership to American society.
But the Brookings scholar adds that church groups run great risks by becoming too affiliated with just one political party. By doing so, they lose credibility with many of their parishioners.
At the same time, churches involve themselves in ''causes'' - such as disarmament, tax questions, and jobs plans - at their own peril, says Reichley.
Some church leaders insist that certain political and social issues have such strong moral implications that the religious community can't ignore them. This is the bishops' position regarding the nuclear question.
The Right Rev. John T. Walker, bishop of the Episcopal Diocese of Washington, D.C., and dean of the National Cathedral, considers both world peace and civil rights as proper subjects for the clergy.
However, Bishop Walker concedes: ''As the church takes stronger stands on political issues - like nuclear war and concern for the poor - it will find itself in more and more difficulty with those in and out of government.''