More than 30 evangelical Christian leaders and Orthodox Jewish rabbis representing the top leadership of the Rabbinical Council of America met Thursday in Washington to forge an alliance of political support for Israel.

The two-hour meeting, held at the Israeli Embassy, was described later by both groups as a first step in creating a new political offensive by a rabbinical organization and the evangelical Christian "new right." The rabbinical council, the largest in the country, has a membership of more than 1,000 Orthodox rabbis.

Rabbi Gilbert Klaperman, president of the rabbinical council, said at a press conference held by the two groups at the Shoreham Hotel that both agreed on at least two concrete areas of concern on Israel:

"We deplore the president's continued pressure on Israel to depart from Lebanon without putting similar pressure on Syria," Klaperman said. (The Reagan administration has called for the withdrawal of all foreign forces from Lebanon, including Syria's and the Palestine Liberation Organization's, but its emphasis in current negotiations is on obtaining Israeli agreement to a pull-out.) The two groups also want the United States to recognize Jerusalem as the capital of Israel, Klaperman said.

The two groups said the meeting may become the first step in an alliance on domestic and other foreign issues as well. Both groups oppose abortion, support tuition tax credits or other means of public funds for private religious schools, and are worried over suppression of Christianity and Judaism in the Soviet Union.

"We have no idea where the seeds will sprout," said Klaperman.

Rabbi Abner Weiss, chairman of the rabbinical council's Israel Commission, said both groups are "frightened" by expansion of international atheism. Rabbi Rafael G. Grossman of Memphis, a regional vice president of the rabbinical council, said the two groups fear a "secularization of America."

The evangelical delegation's support of Israel is focused on the evangelical view of Biblical prophecies about the return of Jews to Israel before the second coming of Jesus Christ and a political conviction that support of Israel is strategically necessary.

"Israel is our best friend in that part of the world," said Ed McAteer, president of the Religious Roundtable.

Other evangelical leaders at the press conference included John Cummuta, operations manager of the National Religious Broadcasters; the Rev. Dr. Adrian Rogers, former president of the Southern Baptist Convention, and the Rev. Dr. John Walvord, president of the Dallas Theological Seminary. Walvord said he believes God has "blessed America" because of its support of Israel.

The meeting was the latest on Israel in recent months between evangelical Christian leaders and Jewish leaders. The common issue is set against decades of suspicion stemming from evangelical attempts to convert Jews to Christianity. "We're aware of that the proselytizing tradition ," Klaperman said prior to the meeting. "But we're also aware of their passionate concern for Israel."

The new alliance comes at a time of friction between portions of the Jewish community and main line Protestant denominations, partly because of criticism last year of Israel's invasion of Lebanon. The evangelical camp hailed the invasion.