A GOOD WAY TO DISRUPT any dinnertime conversation is to turn the topic to either politics or religion. So it is only natural that when the two become fused together into a national debate on the proper relationship between what is Caesar's and what is God's, the recipe is there for an explosion of passion and emotion.

Education Secretary William J. Bennett sparked the current debate with his unusual Aug. 7 speech to a Catholic lay organization, in which he waxed theocratic, quoted Abraham Lincoln waxing theocratic and made an emotive appeal to inject our public schools with a dose of religion in order to restore America's shaken value structure and set us right with our "Judeo-Christian tradition."

Congress, coming back from an August recess this week, will have to take up the debate, with a raft of church-state issues on the agenda -- school prayer bills, a forthcoming administration proposal for tuition tax credits and a voucher plan. With tuition tax credits, parents would be allowed a credit on their federal income tax returns for money spent on private education. The vouchers would provide federal chits to parents who would give them to either private or public schools to pay for education. These represent the practical political manifestations of the administration's newest divine crusade.

This debate is fraught with confusion in trying to reconcile this nation's new religious fervor with its equally passionate secularism. It's a debate that confuses Americans' sectarian beliefs with what historians have called America's "civil religion."

The concept of a civil religion is an old one, and it helps explain why this country is at once both deeply religious in its values and vehemently secular in its institutions.

The concept sheds some light on why Americans simultaneously tell pollsters that they are religious (leading to the conclusion that we are a devout people) but that they disbelieve almost every article of faith, like the existence of heaven (leading to the conclusion that we are the most secular, non- religious people on earth). It is a concept that, according to religious sociologist Robert Bellah's essay in 1967 on civil religion, "fuses God, country and flag . . . to attack non-conformist and liberal ideas." At its worst, it is an ideology that has led America into foreign entanglements that we sometimes pursue as if they were holy wars.

In that article, entitled "Civil Religion in America," Bellah described it as "a theme that lies very deep in American tradition, namely, the obligation, both collective and individual, to carry out God's will on earth." Religious historian Martin E. Marty said in his book, "Pilgrims in Their Own Land," that the civil religion "finds its true home in aspects of the American legal tradition, its established church in the public schools, its creed in the Declaration, its prophecies in the most compelling lines of presidential addresses, its psalms in some American poetry, its passion in the cries by citizens at the deepest crises of American life."

Understanding of this concept explains Jefferson's references to a "Creator" who gave legitimacy to the new nation and entrusted it with its sense of mission.

In essence, the American civil religion has as a major article of faith a belief in the moral supremacy of American democracy, and it venerates the American Way of Life. It is our "super-religion," transcending, but not supplanting, all other faiths. As Will Herberg writes in his classic "Protestant, Catholic, Jew," the American-Way-of-Life-as-religion "embraces such seemingly incongruous elements as sanitary plumbing and freedom of opportunity, Coca-Cola and an intense faith in education -- all felt as moral questions relating to the proper way of life."

Thus it has been with self-righteous conviction, writes Herberg, that we enter crusades against communism, which is considered evil for no other reason than because it runs counter to The American Way of Life.

Understanding that reasoning helps explain why Reagan, Falwell and the religious right would prefer to side with the white minority regime in South Africa rather than take the risk that a nation claiming to subscribe to democratic institutions would be lost to communism. It is, after all, part of the American mission not only to celebrate democracy, but to export it.

If there is any doubt that Reagan, Bennett and the religious right are adherents to the American civil religion, recall the lines from Reagan's 1980 speech to the Republican national convention in Detroit: "Can we doubt that only a Divine Providence placed this land, this island of freedom, here as a refuge for all those people in the world who yearn to breathe freely?" Reagan asked, before suggesting that the conventioneers "begin our crusade joined together in a moment of silent prayer."

Bennett, speaking last April, said, "Strictly speaking, the United States did not simply develop. Rather, the United States was created (italics mine) in order to realize a specific political vision."

Referring to the civil religion in order to promote specific teachings conflicts with one of the civil religion's founding tenets. That tenet acknowledges and celebrates the fact that this is a diverse nation. It holds that the civil religion must remain aloof from specific sectarian goals dear to many of those who refer to the civil religion to win popular appeal. Thus an attempt to mix the two on a practical level engenders contradiction, and may be doomed.

This is not the only complication in the situation.

While Bennett levels charges of anti- clericism at the courts, the advocates of a strict church-state separation invoke a mythical wall between the two, ignoring the existing web of church-state entanglements from tax-free property to official incantations at public ceremonies.

At the same time, some political observers see Bennett playing practical politics, trying to forge an unlikely alliance between conservative fundamentalists (strongest in the South and Sunbelt states) and Catholics (mostly based in large urban centers of the Northeast and Midwest).

However, this is not really a debate over religion, or even over school prayer and vouchers. Rather, this debate is over values, and what conservatives see as a breakdown in America's social and moral fabric. The schools have become the ideological battleground between those who believe in the existence of absolute rights and wrongs to which all Americans must be told to adhere, and those who think that individuals are obligated and have the right to decide for themselves between right and wrong.

The first group sees its critics as amoral, even immoral, Godless degenerates, who through their rejection of basic values are repudiating the sacred and celebrated "American Way of Life." A more merciful view is that the degeneracy is not their own doing, but the fault of the public school system which has failed to transmit proper values -- love of God, love of the flag, and by extension the moral goals of Ronald Reagan. The second group tends to see the Jerry Falwells and Bill Bennetts trying to impose their conservative political agenda on the nation by giving it the force of Divine Covenant.

Preaching for the conservatives is Bennett, but he is taking his cue from Reagan himself. In a speech to the Knights of Columbus three years ago, Reagan listed the universal American values as work, family, neighborhood, religion and personal freedom. Bennett gave those themes their practical political potency in a speech April 19 to the Ethics and Public Policy Center, when he said the "primordial task of any school system is the transmission of social and political values."

Undersecretary Gary Bauer, Bennett's chief link to the New Right groups, shifted the character of the debate into a running dialogue of national morality in Cincinnati on Sept. 5. In a speech before a conference on pornography, Bauer blamed pornography, drug abuse, youth suicide and the other sins of society on the rise of "value-neutral" education that flourished in the public schools of the 1960s.

The administration approach to decaying morality is a one-two punch. The first punch is to put religion back in the public schools by putting prayer back in public schools. The second punch is tax credits and vouchers to make it easier for parents to move children out of public schools and into schools with values more to their liking.

The values that Reagan, Bennett and the religious right espouse are Americans' common sense of justice, of civil liberties endowed by a "Creator" and self-government as an extension of our commonly held belief in the dignity of man. Americans all share these beliefs, Reagan said, "whatever their social, ethnic or religious heritage." Added Bennett: "From the Judeo-Chri stian tradition come our values, our principles, the animating spirit of our institutions." Even columnist George Will chimed in, saying Abraham Lincoln believed that "All Americans are equally American . . . by virtue of their sharing the essential moral sentiments of the Judeo-Christian tradition."

They are all partially correct. Americans do share beliefs and principles. We are, in that sense, a religious people.

The "Judeo-Christian tradition" is an oft-repeated phrase whose validity and meaning are much in dispute -- after all, there are profound differences between Jews and Christians. It is also a phrase that is easy to use for political purposes.

More certainly, the common values -- the religion -- that Reagan, Bennett, Will and Co. are appealing to is our civil religion or public religion, that uniquely American national faith that believes God put this country here to fulfill His divine mission on earth. It is, strictly speaking, our national ideology.

That vision, or sense of mission, has been invoked by presidents past, by Woodrow Wilson and Franklin Roosevelt, and even by the first Catholic president, John Kennedy who made no less than a half-dozen references to God and the Almighty in his innaugural address.

But the "God" of Kennedy's public speech and the "Creator" of the Declaration is the God of our civil religion and, as such, believed to be the source of American power and legitimacy on earth.

This is also a supreme being which in its traditional civil-religion distance from particular sectarian beliefs reflects the God of many of our deist founders, who used His name in the Declaration. This 18th century deity had set the universe in motion like a clock, but like a clockmaker remained distant from His creation -- in other words, deists believed that God did not interfere in the laws of the universe.

Presidents and politicians since the founding have appealed to this Higher Being without wading into the quagmire of sectarian differences, usually avoiding references to "Christ our Lord" or "Jehovah" or a "Holy Spirit." That man derives his power from above is a concept that the vast majority of Americans share regardless of their affiliation -- and it is shared precisely because it is vague, avoiding denominational or sectarian references.

The problem is that some of the religious and moral crusaders on the right are appealing to the ideal of American civil religion while trying to use its emotional and spiritual appeal to achieve sectarian goals. This exercise is on a collision course with American tradition -- one of the founding tenets of the civil religion is that it eschews sectarianism.

Recent examples include arguments over the teaching of creationism vs. evolution in the schools, over sex education, over abortion and over attitudes toward atheistic communist philosophy and governments. Issues that some groups regard as ethical, such as pornography, become religious to other groups. The Rev. Jerry Falwell can advocate support for the white South African regime and urge all "good Christians to buy krugerrands" while certain clerics can espouse left- wing politics and call it "liberation theology."

Attempting to fit the civil religion in the same government program with various sectarian goals risks breakdown of the national religious consensus, since the values of right and wrong are the essence of sectarian factionalism on issues from divorce to dancing and playing cards; from women's rights to drinking coffee and serving in the armed services; from abortion to transubstantiation.

Theologians of various stripes have argued over these questions for decades. And for believers, the interpretations become matters of faith. To put these questions into a political realm makes for intractable disputes since matters of faith cannot be compromised, while compromise is the essence of politics.

Debates over federal aid to religious schools show yet again the potential for pitting faith against faith, sect against sect. Southern fundamentalist parents may want tax breaks and vouchers to send their children to segregated Bible academies, but many may resent federal funds going to Catholic parents whom some still privately deride as "ring-kissers." The coalition would also be endangered by ethnic and rural/urban divisions.

Ironically, the twin issues of tax breaks and vouchers also raise the specter of heightened government involvement in ecclesiastical concerns -- exactly the kind of thing that the "less-government" adherents would abhor were it coming from the liberal left.

Take just one hypothetical examples, not so far-fetched: Suppose Congress did pass a laws giving vouchers and tax breaks to parents who enroll their children in religiously affiliated schools. Then suppose a theological heir to the Rev. Jim Jones decided to open a People's Temple Day School and found enough true-believer parents who wanted to instill their children with this oddball faith.

Government then has two choices. It can deny any parent the right to use federal tax credits or vouchers to support in any way the People's Temple Day School. Or, it can turn a blind eye and appeal to religious tolerance. The public outcry would no doubt call for some government restrictions on what schools must teach before parents qualify for voucher money or tax breaks. And then the government would be in the business of choosing which religions are legitimate and which ones are not.

The ones selected as "legitimate," and deserving of parental vouchers -- probably the traditional ones -- would be accused of being the government's "established" religions, which is exactly the situation that Jefferson and the Founders wished to avoid.

Quotations from the Founding Fathers have been so misused and taken out of context that they have almost become irrelevant to any meaningful debate. But it is worth considering Jefferson's words about government aid to churches.

"We believe that preachers should be supported only by voluntary contributions from the people," he said in a 1776 Declaration of the Virginia Association of Baptists.

Government aid made preachers accountable to government, he said, and "the consequence of this is that those whom the state employs in its service it has a right to regulate and dictate to; it may judge and determine who shall preach; when and where they shall preach; and what they must preach."

One hundred years later, Gen. U.S. Grant, speaking to the Army of Tennessee on the anniversary of American independence, said: "Encourage free schools, and resolve that not one dollar appropriated for their support shall be appropriated to the support of any sectarian schools. Resolve that neither the State nor nation, nor both combined, shall support institutions of learning other than those sufficient to afford every child growing up in the land the opportunity of a good common- school education, unmixed with sectarian, pagan, or atheistical dogmas. Leave the matter of religion to the family altar, the church, and the private school, supported entirely by private contributions. Keep the church and the state forever separate."

The Education Department's exact proposals on the touchy issues of tuition tax credits and vouchers have yet to come down. But to sell it to a traditionally skeptical Congress, Bennett and his supporters will need to do more than sermonize about the necessity for choice, without addressing some of the very real concerns laid down in the writings of Jefferson and Grant and others. They will have to fit their proposals into the American religious tradition which is an American civil religion that has divided our public life from private beliefs.

But likewise the critics will need more to shoot down the proposals than the expressions of outrage and ritualistic appeals to the separation of church and state which does not now exist. The separation is an illusion that ignores student loan money flowing into colleges like Georgetown and Catholic University; it ignores tax-exempt church land and public school textbooks in parochial school classrooms.

If the critics have substantive arguments against tax credits, vouchers and school prayer, they must bring those to the forefront of the debate. They must address themselves to what many Americans see as a breakdown in the nation's social fabric, present alternative explanations and propose their own civil solutions. Otherwise, the debating ground is left to those who argue that the answer to today's pressing social problems lies On High.