At a time when Pope John Paul II is calling on wayward Roman Catholics to hew closely to church teaching, a significant number of priests and nuns in the United States are questioning many of the church's edicts.

Celibacy for priests, the Vatican's opposition to the ordination of women, and its prohibition against artificial birth control are as likely to be disputed by priests and nuns as supported, The Times Poll has found.

But despite dissent over certain issues--none of which go to the doctrinal core of Catholic faith--priests and nuns are highly selective in challenging moral teachings or traditions.

By overwhelming majorities, priests and nuns are in accord with their church in its opposition to abortion, assisting in euthanasia, sexual relations between unmarried couples, relations outside marriage, homosexual behavior and marriages between homosexual couples.

And unlike members of the laity, priests and nuns view moral and spiritual issues--not economic concerns--as the greatest problem facing the country and families today.

Loyalty to the church as an institution is high among both groups, and contrary to popular perceptions, so is their morale. When asked if they would take their vows again, 87% of priests and 88% of nuns said they would. Although 59% of priests say that the church should ordain married priests, only 15% said they would wed if permitted. The American media's coverage of the church was considered too negative by 84% of priests and 71% of nuns.

Although there was wider disagreement over whether the Pope is too conservative on moral issues, he earned high ratings for his overall job performance. A 74% majority of priests and 70% of nuns approve of the way John Paul is handling his duties as Pope. Local bishops or the superiors of orders earned similar marks.

"The good news is that the much-advertised morale crisis in the priesthood affects only a small number of priests. The bad news is that a large proportion of the Catholic clergy do not accept many of the sexual teachings on which the present papacy has placed great emphasis," Father Andrew Greeley, a Catholic sociologist and author at the University of Chicago, said after analyzing The Times' data.

The results are based on written responses from 2,087 Roman Catholic priests and 1,049 Roman Catholic nuns in dioceses across the United States, including Puerto Rico--a 42% return. The survey, which was self-administered and anonymous, was conducted by mail from September, 1993, through January. The margin of sampling error for the priests' survey is plus or minus 3 percentage points; for nuns it is plus or minus 4 points.

The poll sparked controversy even before it was completed. Shortly after the questionnaires were sent out, Cardinal Roger M. Mahony, the archbishop of Los Angeles, publicly accused the newspaper of preparing to engage in "the American media's favorite pastime--Catholic-bashing." Mahony said he was particularly offended by questions dealing with sexual issues.

Three independent experts, however, said the Times' data is credible and significant. Although they noted that the 42% return rate was lower than some previous samples and could result in some bias, they did not consider it a serious problem. Church sociologist Dean Hoge of Catholic University of America in Washington said: "If there is a bias, it's not a serious bias. . . . There is nothing in this poll which is so far off as to make me doubt the validity of the data."

The striking selectivity with which priests and nuns pick and choose among church teachings and traditions comes at a time when John Paul has issued a ringing denunciation of what has come to be called cafeteria Catholicism.

Calling it a genuine crisis, the pontiff underscored his alarm in August when he issued what was described as the most important encyclical of his pontificate, "Veritatis Splendor," or "Splendor of the Truth." In it, John Paul warned of "an overall and systematic calling into question of traditional moral doctrine."

But in the United States, the Times Poll indicates that Catholic bishops will not have an easy time carrying out the uncompromising directive embodied in "Veritatis Splendor": "To be vigilant that the word of God is faithfully taught" and that Jesus' commandments and teachings be "reverently preserved, faithfully expounded and correctly applied in different times and places."

More than other factors, the poll found that priests and nuns were divided in their views by their age and whether they classify themselves as religious liberals, moderates or conservatives.

One out of five priests--21%--say they frequently counsel Catholics to follow a course of action that contradicts official church teaching on morals, the poll found. Among priests age 35 and younger, 27% do so, as do 29% of priests between the ages of 36 and 50. The oldest priests are the most orthodox, with only 10% saying they frequently offer advice that conflicts with church teaching.

Despite the Pope's insistence that contraception is an "intrinsically evil" act that cannot be mitigated by circumstances, the Times Poll found that 44% of priests and nuns believe that artificial birth control for married couples is seldom or never a sin, while 49% of priests and 37% of nuns said it is always or often a sin.

The use of condoms as protection against AIDS was seen as always or often a sin by 46% of priests and 33% of nuns, but 41% of priests and 42% of nuns held that it was seldom or never a sin. In contrast, 16% of Catholic laity believe that using condoms to prevent the spread of AIDS is wrong, according to a CNN/USA Today Gallup Poll conducted in August.

The Times also found that 84% of priests believe that premarital sex is always or often a sin. In the August Gallup poll, 48% of rank-and-file Catholics said sex outside marriage was always wrong.