The foreign mission board of the Southern Baptist Convention, the nation's largest Protestant denomination and one of the most evangelistically aggressive, is resisting expansion into Canada. The reason: the powerful SBC is worried about its image as a "colonial" institution.

There are those who view Southern Baptists as "an empire on the march," bent on extending "our tentacles all over the world," explained board official Don Kammerdiener. Changing the SBC constitution to include operation in Canada as well as the United States "would give encouragement to those voices that say, "See, we knew it all along -- Southern Baptists want to take over the rest of the world,"" Kammerdiener added.

R. Keith Parks, president of the foreign mission board, which has missionaries in 99 countries, said he is sympathetic to "evangelistic needs" in Canada, but believes the SBC can help best by encouraging Canadian Baptists "to express themselves in a kind of Baptist organization that would have universal appeal across Canada rather than be seen as simply an appendage to a foreign convention."

The SBC, which developed from an 1845 split of Baptists in America over the issue of slavery, began a vigorous program of establishing congregations in all parts of this country in the years following World War II. Some of that effort spilled over across the border, particularly in the Pacific Northwest.

The question of relations with the Canadian churches surfaces periodically as the 60 Canadian congregations send messengers, as delegates are called, to the annual SBC national convention. Under the SBC's present constitution, full voting participation in the annual conventions is open only to representatives from U.S. churches.

The National Conference of Catholic Bishops, still gasping from the monumental effort of its comprehensive pastoral letter on nuclear warfare, has postponed for at least a year the work on a comparable document on capitalism.

Target date for preliminary draft of the economic document is now mid-1984. The preliminary working title of the proposed pastoral also has been changed from the original "Christianity and Capitalism" to "Catholic Social Teaching and the American Economy."

Archbishop Rembert Weakland of Milwaukee is chairman of the five-bishop committee working on the economic pastoral. He Harvard-trained political scientist-priest, the Rev. Bryan Hehir, generally acknowledged to be the principal author of the war and peace pastoral, is also the staff consultant for the forthcoming work.

The Anti-Defamation League of B'nai B'rith has charged that the Sandinista government of Nicaragua has confiscated Jewish-owned property, including the synagogue in Managua, and forced the Nicaraguan Jewish community into exile.

Rabbi Morton Rosenthal, director of the league's Latin American affairs department, wrote in the ADL bulletin that Jews were driven from Nicaragua both by "subtle and direct threats or by forcible measures."

The Managua synagogue, Rosenthal said, was confiscated and turned into a children's social club after the Sandinista victory. He added that government officials recently told a United Nations Human Rights Committee that the government is considering restoring the synagogue as a place of worship, but noted that "this is a meaningless promise in a country without Jews."

Rosenthal charged that the Sandinista regime's policy toward Jews was influenced by ties with the Palestine Liberation Organization.

A California judge has ruled that Church of Scientology founder L. Ron Hubbard has proved he is not dead. The ruling came in a case filed by the reclusive Hubbard's estranged son, Ronald De Wolf, asking to be made a trustee of his father's estate because, the son claimed, Hubbard was either dead of incompetent to handle his affairs.

Superior Court Judge David Hennigan ruled that a seven-page response to the suit had been written by Hubbard and was not, as De Wolf, who broke from the Scientology movement, charged a forgery by church officials controlling Hubbard's interests. The judge gave De Wolf's attorney three weeks to try to disprove the authenticity of the document.

The National Conference of Catholic Charities has established a legal defense fund to help Catholic Family Services of Amarillo regain United Way funding. The Texas Catholic agency was dropped last year because it assisted employes of Pantex, a nuclear weapons manufacturer, who left their jobs for reasons of conscience . . . Plans for a baseball stadium on the upper New York state site of the original Shaker colony have been held up by a suit filed by eight elderly women -- the last survivors of the 19th century religious colony. The women charge that construction of the stadium would lead to desecration of the community's 450-grave cemetery . . . The Lutheran World Federation has turned down a proposal to beam Christian broadcasts into China because Chinese Christians have indicated such broadcasting from outside China is not helpful . . . Three Midwestern television stations have refused to sell time to the National Council of Churches for a half-hour program featuring the council president, United Methodist Bishop James Armstrong. Six other stations in Indiana and Ohio telecast the program.

PEOPLE: Two clerical couples were appointed to United Methodist churches on the Eastern Shore last week. The Revs. Anne and Mark Pruett-Barnett will serve churches in the Salisbury, Md., area.The Revs. Darlene and Dale Lantz were appointed by Bishop D. Frederick Wertz to Wilmington-area churches.

In New York City, the Rev. Suzan Denise Johnson was installed as pastor of Mariners' Temple She is believed to be the first black woman pastor of a mainline Baptist church.

Hyman Appleman, a Russian-born Jew who converted to Christianity and became an evangelist, died in Kansas City at 82.

The Rev. Ladislaus A. Iranyi, former provincial of the Washington-based Piarist Fathers, hs been named a bishop to serve the needs of Hungarian Catholics outside Hungary.