Rep. Geraldine A. Ferraro (D-N.Y.) today demanded an apology from President Reagan for what she said was his "disgraceful falsehood" in asserting that the Democratic Party lacked the moral courage to denounce anti-Semitism.

"I will not accept the base implication that my party is soft on anti-Semitism," Ferraro told about 1,000 people at Temple Kehilath Jeshrun, referring to Reagan's comments at a Long Island synagogue last week.

"In an effort to impress his audience, President Reagan insulted it. In an effort to assail us, he debased himself. The president's remark was incorrect, indecent and he should apologize for making it," she said.

But the Democratic vice-presidential nominee also appeared to undercut her own candidacy during an appearance on the "CBS Morning News" today, acknowledging that Vice President Bush currently is more qualified to be president than she is.

Asked about a New York Times endorsement Sunday of Democratic presidential nominee Walter F. Mondale, Ferraro agreed with the editorial's assertion that Bush would be better prepared than she to step into the Oval Office if necessary.

"No doubt about it. He's been there four years," she said. "I would expect that people would say that, or that The Times would because that's a fact. He's been in the White House for four full years. If after four full years you're not better than somebody who's been in Congress for a lesser period, you know, of time, then there's something wrong with you."

Privately, Ferraro's aides winced at her response, Campaign manager John Sasso, in a quick move toward damage control, said Ferraro was talking about public perceptions of her qualifications -- not any personal doubts about her capabilities.

"What she was trying to say was, sure Bush has got some advantages in people's minds because he's been in the White House for four years. It's an honest statement," Sasso said.

In perhaps her toughest speech of the 1984 campaign, Ferraro served notice at the synagogue that religion and politics will continue to provide a major theme as the campaign enters its last week.

The Democrats also are trying to curtail party defections by Jewish voters, who traditionally have been stalwart Democrats. Ferraro aides were visibly uncomfortable when former Democratic presidential contender Jesse L. Jackson, who has been accused of anti-Semitism by some Jewish groups, unexpectedly appeared on the campaign plane to wish her well as the race enters the home stretch.

In her speech, Ferraro said the nation above all needs "a commander in chief, not a keeper of the faith. We need a president who worries about the state of our air and our water, and not his own view of our state of grace.

"We need a president who does everything he can for arms control, and does not let the arms race continue merely because of his own religious belief in the possibility of Armageddon," she added.

Speech writer Fred Martin said Ferraro stayed up hearly until midnight Sunday reworking a draft of today's speech.

Ferraro said the Republican Party has provided a platform for "moral monopolists" to spread their belief that "they are the sole possessors of moral and religious truth."

"America remains the most religious nation on earth, not because our government supports religion, but because government has no role in religion," she said. "Government can be moral -- and it must be moral -- without adopting a religion.Leaders can be moral -- and they should be moral -- without imposing their morality on others."

Ferraro also accused Reagan of revising history in saying last week that American troops were sent to Beirut in 1983 to prevent another Holocaust of Jews.