A LEGAL dispute over the government of the Christian Science Church moved forward this week in a case that is being watched by major religious groups for its First Amendment implications. Lawyers made oral arguments Aug. 28 on a motion for ''summary judgment'' in a case that pits two members of The First Church of Christ, Scientist, in Boston against past and present top church officials. Elizabeth Weaver of Glen Arbor, Mich., and Roy Varner of Houston, Texas, charge that officers of The Mother Church and the Christian Science Publishing Society in Boston ''recklessly and wrongfully'' spent hundreds of millions of dollars on media ventures between 1988 and 1992. They want the Massachusetts Superior Court to enforce their interpretation of church bylaws set forth in the Manual of The Mother Church, the church's constitution, and two deeds of trust, all written by Mary Baker Eddy, the church's founder. The defendants, including the Christian Science Board of Directors, say the court has no jurisdiction to hear the case and that adoption of the plaintiffs' interpretation of the bylaws would amount to an unconstitutional restructuring of church government by the judiciary. Ms. Weaver and Mr. Varner also demand a detailed accounting of church expenses, including for all media ventures, from 1988 to the present. The directors say they have already supplied more financial information than church rules require. The plaintiffs charge that the directors and the Board of Trustees of the Christian Science Publishing Society, which publishes The Christian Science Monitor, exceeded their authority and did not follow proper procedures in funding the media ventures. These include Monitor Radio, which provides daily news programs on public and shortwave radio; a nightly television news broadcast that ran from 1988 to 1992; a cable-TV channel the church sponsored from 1991 to 1992; and a monthly news magazine published from 1988 to 1993. Weaver and Varner say church bylaws require the Committee on Finance to approve any expenditures before they are made and give the committee power to remove a member of the Christian Science Board of Directors. The directors maintain that the Manual bylaws confer no such powers on the committee, which reviews church bills and approves their payment by the treasurer, and that the bylaws in question have never been interpreted in the manner Weaver and Varner suggest. The arguments followed a barrage of legal briefs from both sides over the last several months. Arguing for the defense, Theodore Dinsmoor told Judge Vieri Volterra he should grant the motion because the plaintiffs lack standing to bring a suit, the First Amendment to the United States Constitution bars court adjudication of issues of church government, and it would be imprudent to adjudicate the matter. Mr. Dinsmoor said the church's governing documents - the Manual, an 1892 Deed of Trust for The Mother Church property creating the Christian Science Board of Directors, and an 1898 Deed of Trust creating the Christian Science Publishing Society - create charitable trusts for the benefit of all church members: They do not create private trusts for the plaintiffs. In addition, Dinsmoor said, the governing documents are administrative in nature and therefore do not create distinct contract or property rights for the plaintiffs. Therefore the plaintiffs lack standing to sue. Dinsmoor told the court that a series of decisions by the US Supreme Court and lower courts hold that the First Amendment bars judicial inquiry with respect to matters of internal church organization and governance. These protections, he said, apply to all denominations, regardless of whether they are legally characterized as ''hierarchical'' or ''congregational.'' Finally, Dinsmoor said, even if the court did have jurisdiction to hear the case, it would be imprudent for it to do so ''when there is no concrete dispute over governance,'' other than the plaintiffs' ''idiosyncratic'' interpretation of the bylaws. ''Is it prudent when the implementation of the plaintiffs' views would effectively reorganize The Mother Church, affect its ability to carry out its mission, and shut down The Christian Science Monitor newspaper, the voice of church?'' To do so would impair the church's ability to financially support the Monitor and the church's religious magazines and unconstitutionally put the church in virtual receivership, he said. Arguing for the plaintiffs, Allan van Gestel said the issues were clear: ''At the end of fiscal year 1987, the church had $20 million in surplus funds and a unrestricted balance of more than $100 million. Five years later, at the end of fiscal year 1992, the unrestricted funds were $114 million in the negative. In the same period, the Christian Science Board of Directors and the Board of Trustees of the publishing society spent over $450 million on a TV media blitz. That's what's at stake.'' Mr. van Gestel told Judge Volterra that Dinsmoor had ignored a ruling by Judge J. Harold Flannery denying a previous motion to dismiss. ''This is not an appellate court. Nothing different has happened,'' he said, insisting that Judge Flannery had heard all the same arguments and seen all the church governing documents in question. (The defense, in a legal brief, argues that a motion for summary judgment and a motion to dismiss operate under different rules of procedure - in a motion to dismiss, a judge must accept a plaintiff's allegations as true - and that Flannery specifically refused to consider ''relevant church documents'' in his decision.) DISAGREEING with Dinsmoor's characterization of the meaning of church bylaws regarding the finance committee and publishing society spending, Van Gestel said that the true meaning should be explored in a full trial, not in a hearing for summary judgment. (A summary judgment is a final decision in a case without lengthy presentation of evidence.) Asked by Volterra what relief he was seeking, Van Gestel replied, ''We are asking you to direct the Christian Science Board of Directors to read and apply [the bylaws].'' He asked the judge not to overturn Flannery's finding. If the court takes jurisdiction, and particularly if its decision to do so is upheld by the state's Supreme Judicial Court, the case ''would have implications throughout the religious community,'' says J. Brent Walker, a lawyer with the Baptist Joint Committee on Public Affairs in Washington, D.C. ''The rub comes if under the guise of 'neutral principles' [of law] the court is being asked to decide theological issues. That would give us cause for concern.'' Volterra promised a decision ''soon.''