Diversity of US flock may test Pope's resolve. Pope John Paul II begins his US visit today. Vatican and host-city planning has been meticulous. Stories below, Pages 4 and 10.

As Pope John Paul II starts his 10-day visit to the United States and Canada today, he will be surrounded by an American people who are strongly divided over social issues but narrowing their religious differences. This seems to be the consensus of church people and others - both Roman Catholic and not - interviewed about the possible impact of the Pontiff's visit. His trip starts in Miami, proceeds along the Sunbelt to California, and ends with a visit with Indians and Eskimos in Canada's Northwest Territories on Sept. 20.

Protestant theologian Martin Marty says a big change among American Catholics occurred largely as a result of the Second Vatican Council, which ended in 1965.

``Catholicism is now in the main line,'' says Professor Marty. ``Take a look at the American [Catholic] church. It exists in the midst of religious freedom - freedom of choice.

``People pick and choose on issues like birth control and abortion. They won't come [be won over] by whip cracking,'' the theologian adds. ``We're a pluralistic society. And he [the Pope] can only make it by persuasion - not coercion.''

Marty and others expect John Paul to use his visit here to try to forge new understanding between Catholics and non-Catholics.

Both Catholic and non-Catholic women plan to demonstrate their opposition to the Vatican's stands on a range of social issues - such as abortion, birth control, surrogacy and alternative birth means, and the role of women in the church.

But the Pope is not likely to engage in open confrontation with these groups.

And although several Protestant fundamentalist groups are boycotting or ignoring the visit, most are putting out the welcome mat.

Key meetings with US Jewish leaders come at the very beginning, today and tomorrow in Miami. Rabbi A. James Rubin, director of Interreligious Affairs with the American Jewish Committee, will attend the meetings. He admits that ``there has been a lot of turbulence in Jewish-Roman Catholic relations ... particularly over the Waldheim thing.''

Jews have been sharply critical over the Pope's audience in June with Austrian President Kurt Waldheim, who has been implicated in the persecution of Jews as an officer in the German Army during World War II.

Rabbi Rubin is optimistic that something ``substantive'' will come out of the Pope's Miami meetings - maybe even a ``Papal encyclical on anti-Semitism,'' he says.

``We must realize that a lot of progress has been made,'' the Jewish leader insists. ``Twenty-five years ago most Jews didn't want to deal with the Vatican. We have made more progress in the past decade [toward bettering Jewish-Roman Catholic relations] than in the previous 1,900 years.''

But he adds: ``There are still those in both communities who want to boycott or picket. They're wrong. And we must not capitulate to extremists.''

The Rev. Arie Brouwer, general secretary of the National Council of Churches (NCC), talks of the Pope's visit as ``significant in the area of the symbol of the event.''

He also sees the visit as an opportunity for leaders of all churches and religious groups to share ideas. ``There's a convergence going on.... All groups are moving toward one another. It is important for the NCC to be involved. It could lead to significant things,'' Mr. Brouwer says.

The Rev. Thomas Stahel, a Catholic priest and associate editor of America, a prestigious Jesuit scholarly magazine, stresses that the Pope's itinerary - including meetings with Jews in Miami; Christians in Columbia, S.C.; blacks in New Orleans; Hispanics in San Antonio; and American Indians in Phoenix - ``is an acknowledgment of religious diversity in the US.

``He wants to reach out to different communities. Those things that divide Christian from Christian and Jew from Christian are not as great as those that divide believers from nonbelievers,'' Fr. Stahel explains.

Stahel stresses, however, that the Pope will likely have a clear message to American Catholics to be ``less materialistic ... [and] to be aware of the needs of poor people overseas.''

``Roman Catholics lead their moral lives in ways that are typical of their society,'' he says. ``And that in a way disturbs the Pope. He would hope that Roman Catholics would lead lives that are countercultural, not only in terms of sexual morality but [in terms of] being less materialistic.''

The Jesuit scholar calls John Paul II the ``chief TV evangelist in the world today.''

``He stands for Gospel values.''

George Williams, professor emeritus of church history at the Harvard Divinity School and one of the nation's leading authorities on the Pope, will be among a select few to meet with the Pontiff in a private meeting in Columbia.

Professor Williams, who is not a Roman Catholic, insists that this visit is ``significant as to the whole of American society.''

``It will draw attention to the bicentennial ... [to] the religious diversity in the US.

``We are a Christian superpower. We are a homogenized society. What Catholic women are saying, Methodist women are saying.

``The Pope will address moral and social issues. And we will all be encouraged to think further,'' Williams explains.