Debate over issues of religious freedom will sharpen in '84

New challenges, some of them very formidable, are in store next year for defenders of the First Amendment's constitutional guarantees of separation of church and state.

Among them: renewed efforts by the Reagan administration to push for a constitutional amendment to allow prayer in the public schools; moves toward government regulation of church schools; advancement of plans for official diplomatic ties with the Vatican; and a thrust on new fronts to allow tuition tax credits for students who attend parochial schools.

Further, many of those who man the so-called ''wall of separation'' - including the American Civil Liberties Union, Americans United for Separation of Church and State, and several civil rights and church rights groups - say the public should be particularly aware of what some view as strong stances by the state today to curtail parental choice in regard to the upbringing of children. Many of the controversial cases in this area revolve around practice of religious beliefs, including reliance on prayer for healing.

As courts have explored these cases, public interest has grown. In Tennessee, for instance, a child has been ordered to accept ongoing medical treatment, over the objection of her parents, for what has been diagnosed as a serious bone disease. Both the girl and her family say they want to rely solely on their faith in God to resolve the situation. This case will likely be appealed to the US Supreme Court on First Amendment grounds.

In quite a different kind of case in Michigan, parents who lost a child and became disenchanted with their long-held religious beliefs sued the church and two of its practitioners for damages as part of a campaign to increase state regulation of the church's healing practices in regard to children. A judge dropped all charges as being in conflict with religious rights guaranteed under the First Amendment. Plaintiffs in this case are appealing the decision.

Related issues involve controversial state mandates that support systems be used to extend human lives, including that of severely physically impaired infants, over the objection of parents. While the most publicized of these cases do not specifically relate to religious beliefs, some say the broader issue of individual determination vs. state control is pertinent.

A l983 scorecard on pertinent church/state issues shows these developments:

* School prayer. Advocates of a constitutional amendment allowing voluntary prayer or a ''moment of silence'' in public schools suffered a severe setback when a New Jersey judge, in a sweeping opinion, hoisted the First Amendment in striking down that state's ''silence'' law. Twenty states, however, still have such statutes on the books. And although the US Supreme Court recently refused to review a federal district court ruling in New Mexico outlawing a ''moment of silence,'' the high court may yet have to resolve the issue.

* Tuition tax credits. The Senate's overwhelming defeat of this type of public aid for parochial schools is causing backers to reassess their tactics.

Some believe that next year's proposed federal legislation might be more broadly written to include deductions for parents of both public and private school parents. (Defeated legislation, strongly backed by the Reagan administration, singled out private, and parochial, school students for benefits.)

In a narrow 5-to-4 decision earlier this year, the US Supreme Court upheld a Minnesota law that allows tax deductions for church-related school expenses because the statute included benefits for public school attendees.

* Tax breaks, federal aid to religious schools. In a clear-cut, 8 to 1, decision, the Supreme Court chose civil liberties protections over religious convictions in the Bob Jones University case. The court upheld the federal government's right to deny tax exemption to schools whose religious tenets require racial discrimination.

Some church leaders say this decision could give the government the right to deny such extemptions to any church which promotes policies it disagrees with.

In a semi-related case, the court will decide in 1984 whether students at Grove City College, a school which refuses to sign anti-sex bias federal guidelines (although it vows it practices no discrimination), are eligible for government grants and loans. Many church-related colleges who shun federal ''ties,'' but whose students are dependent upon government aid, are vitally concerned about the outcome of this case.

* Ambassador to the Vatican. The proposal for US diplomatic relations with the Vatican appeared to be headed for approval, as Congress quickly and quietly in November passed a measure dropping a 116-year-old ban on using funds to maintain a diplomatic mission to the papacy. However, a lobbying campaign to dissuade President Reagan from formalizing such a move now is being spearheaded by many non-Roman Catholic religious groups.