Lew Lehrman stood on the foredeck of the former presidential yacht Sequoia last night and watched the sun set over Hains Point.

"These have been happy, happy days," he said.

Lehrman recently announced that he has completed his conversion from Judaism to Catholicism. He was a friend of the late Terence Cardinal Cooke and had been quietly active in the church for at least 20 years, but the news came as a shock to most who had followed Lehrman's political rise -- he narrowly lost the 1982 New York gubernatorial race to Mario Cuomo.

Last night, in his capacity as chairman of the conservative lobbying group, Citizens for America (CFA), Lehrman was playing host to a flotilla of power and fame: former Secretary of State Alexander Haig, arms negotiator Kenneth Adelman, singer Anita Bryant, Secretary of Health and Human Services Margaret Heckler, CIA Director William Casey, Agriculture Secretary John Block and William Lucas, who recently left the Democrats for the Republicans to run for governor in Michigan.

"I have a tremendous amount of respect for Lew's decision, his conscience and his commitment" Heckler said. "Of course, I speak with some bias. I'm Catholic. I salute him so strongly because he's a public-oriented individual who followed his conscience despite any political reverberations . . . And I think he made the right choice!"

Haig said, "I don't think it will hurt Lew politically. No, I think Americans have always considered religion a personal thing. But then I may have a prejudice because I'm Catholic."

Adelman said, "I guess what it boils down to is, it's Lew Lehrman's own affair. He's a very intense person, believes in things intensely, whether it's secular or religious."

For his own part, Lehrman said, "I'd rather talk about public matters."

And in that arena, Lehrman will meet soon with representatives of anti-Marxist leaders from Nicaragua, Cambodia, Angola, Afghanistan and elsewhere.

"We want to exhibit solidarity with all the anti-Marxist movements in the world," he said.

Jack Abramoff, executive director of CFA, would say only that the meeting would take place "somewhere in the world" and "within the next few weeks." But another knowledgeable source said that the conference "will be in Africa next week."

CFA was formed two years ago, with Ronald Reagan's blessing, as a lobbying group that would, in Lehrman's words, "push the president's programs forward." The group's financial supporters include some of the wealthiest business executives in the country: industrialist J. Peter Grace, brewer Joseph Coors, oil magnate Nelson Bunker Hunt, risk arbitrageur Ivan Boesky and oil executive T. Boone Pickens.

Just before a mesquite-grilled dinner featuring buffalo meat and smoked quail was served, Abramoff spoke of how his boss has handled the publicity surrounding his conversion:

"Lew's made that decision for himself. He's still marching along, doing the job the president asked him to do."

"Yes," Lehrman said, "I'm just doing my work as productively as I can."