Prime Minister Menachem Begin appealed tonight to a group of fundamentalist Christians from around the world to help Israel retain control of the occupied West Bank. He declared, "This land as a right belongs to the Jewish people."

Begin was speaking to about 4,000 people at an annual gathering here sponsored by the International Christian Embassy of Jerusalem, an organization that strongly shares Begin's biblical view of the West Bank as an integral part of the historic "land of Israel."

Begin made no mention of the most burning issue in Israel--the massacre of Palestinian refugees while Israel occupied West Beirut.

The Christian organization, in a press release, said it deplored the massacre and believed that Israel had made "a serious mistake" in sending the Lebanese Christian militia units into the Shatila and Sabra refugee camps. But the organization said the presence of Israeli troops in the area prevented even worse bloodshed.

Israeli television broadcast an interview Sunday with a man who identified himself as a Lebanese Christian militia commander, who said the international outcry following the massacre in Beirut was "much ado about nothing," The Associated Press reported.

"I was in Shatila and Sabra, and I killed Palestinians," the broadcast quoted the man as saying off camera. "I killed only 15 Palestinians in the camps, but I will continue to kill them all my life."

[The television said the man, who called himself Michael, refused to repeat this statement on camera. Asked on camera if he participated in the killing, he said, "I refuse to reply because this concerns only me."]