Teaching moral standards and religious elements of history, generally shunned by public schools in recent decades, seems to be making a sporadic but growing comeback.

This is the assessment of specialists in the field who cite accumulating evidence of the shift, which they say is urgently needed to overcome a huge gap in educating the young.The situation "has been pathetic," educator Charles R. Kniker said of the failure of recent decades to teach religion's pervasive historical and social influences.

The omission has been documented in numerous studies of textbooks. But the ignored influences and effects of religion gradually and sporadically are being restored, Kniker said.

"It's slow going, but it's a clear phenomenon," he said in an interview. "There's a major growth of interest in academic study about religion in the schools. It's been a wilderness, but certainly changes are going on."

Kniker, professor of education at Iowa State University and editor of the journal Religion & Public Education, has made a national survey of state policies on teaching about religion and moral values.

Results showed a spotty pattern but indicated developing concern in that field.

Since the survey broke new ground, however, prior data was lacking with which to compare the results.

"The main purpose was to get a big snapshot of where we are now in this country," a "base line study to see what is the reality" so comparisons can be made with it in the future, he said.

Thirteen states permit teaching about religion in social studies, while typically prohibiting indoctrination in a religion's beliefs. Alabama, for example, allows "religious facts only."

Forty-one states have laws or guidelines on citizenship or character education and 20 states mention moral-spiritual values. But some indicated that teaching them was taboo or was limited to "democratic values."

Twenty states allow observance of a moment of silence, none mentioning that the practice replaced school prayer. Recitation in schools of the Pledge of Allegiance is required in 19 states, while many make participation voluntary.

Charles C. Haynes of Washington, D.C., president of the National Council on Religion and Public Education, which publishes the journal edited by Kniker, said:

"Changes are coming very rapidly, encouraging more teaching about religion in history and teaching of values. Many districts are adopting new policies . . . The change is quite dramatic. It's now irreversible."

Kniker said expulsion of religious knowledge from schools stemmed from misinterpretations of the 1962-63 Supreme Court decisions banning sponsored prayer and Bible devotionals.

Schools and textbook publishers purged virtually any religious reference, fearing controversy, even though the court had said study about religion was essential to education, he said.

Kniker said present changes in attitudes resulted from rising evangelical concern and from many studies showing the stark absence of religious facts from classroom versions of history and society.

School board and teacher requests for guidance materials have soared, prompting the National Council on Religion and Public Education's distribution center at Iowa State University in Ames to open a telephone service, Kniker said.

More than 500,000 copies of the pamphlet "Religion in the Public School Curriculum, Questions and Answers," which was put together by a wide array of educational and religious organizations, have gone to school officials and others.