While thousands of demonstrators protested in the streets against his policies, President Reagan tonight compared himself to Franklin D. Roosevelt and said that his budget-cutting and tax-reduction programs are designed to help the poor and needy rather than hurt them.

But there was skepticism in the streets outside the Hilton Hotel, where Reagan was receiving a brotherhood award from the National Conference of Christians and Jews.

A crowd estimated at 10,000 by Deputy Police Commissioner Alice McGillion gathered to oppose Reagan's economic programs and U.S. involvement in El Salvador. About 500 police, some on horseback, ringed the crowd, which stretched for four blocks along the Avenue of the Americas. There were no reports of violence, and the demonstration broke up around 9 p.m., before Reagan departed.

Inside the hotel, where the president was being honored for his "courageous leadership in governmental, civic and humanitarian affairs," Reagan used the occasion both to denounce "the obscenity of anti-Semitism and racism" and to defend his embattled economic programs.

" . . . Back in the New Deal days, many critics of Franklin Roosevelt accused him of trying to destroy the free enterprise system," Reagan said in his acceptance speech. "FDR's answer was simple: he wasn't out to destroy our political and economic freedom; he was out to save it at a time of severe stress that had caused democracy to crumble and fascism and totalitarianism to rear their ugly heads in so many countries.

"Today I'm accused by some of trying to destroy government's commitment to compassion and to the needy," Reagan said. "Does this bother me? Yes. Like FDR, may I say I'm not trying to destroy what is best in our system of humane, free government; I'm doing everything I can to save it . . . so that enough resources will be left to meet the requirements of the truly needy."

But outside, protesters chanted "Money for jobs, not for war," and "No draft, no war. U.S. out of El Salvador." One person held up a sign that read "Reagan Hood robs the poor to give to the rich." Another sign read "Hey, hey, Uncle Sam, we remake Vietnam."

In his address tonight, Reagan made a brief reference to the protesters, describing them as "those outside who spoke with passion and conviction," and acknowledging their right to protest.

The demonstration was organized by the "Coalition to Roll Back Reaganism," which represents dozens of organizations, including labor unions. It has scheduled a demonstration in Washington for Saturday.

At a morning news conference by Christian and Jewish leaders, Reagan was described as racist, anti-humanitarian and cynical in his disregard for the poor. Rabbi Arnold Jacob Wolf, who received a brotherhood award in 1962, said he was returning it in protest.

Reagan carried New York state but not the city in the 1980 election. From the time last year that the president pressured Congress to approve the sale of the AWACS air reconnaissance system to Saudi Arabia, Reagan supporters in the Jewish community have been urging him to counteract the political effect by reaffirming his commitment to Israel to a major forum.

In his speech tonight the president said that the U.S. commitment to Israel "remains unshakable." But he said that for this commitment to be taken seriously American military strength must be enhanced.

"I am keenly aware of the cost of our defense program and will in the weeks, months and years ahead seek true savings and efficiencies," Reagan said. "But we must refute the misguided belief that our defense program can be arbitrarily reduced and still guarantee our national security."

Reagan also denounced bigotry and prejudice, saying: "No group should be bullied into silence by racial and ethnic slurs, or the fear of them. The language of hate--the obscenity of anti-Semitism and racism--must have no part in our national dialogue."

In celebrating American pluralism and the basic goodness of man, Reagan quoted widely from secular and religious leaders, evoking the memories of Roger Williams, George Washington, John F. Kennedy, William Bradford, Martin Luther King, Thomas Jefferson, Al Smith and Roosevelt. He concluded with a quotation from Anne Frank, a victim of the Nazi Holocaust, who wrote in her diary on July 5, 1944: "In spite of everything I still believe that people are really good at heart."

Reagan is the fourth president of the United States and the first incumbent to receive the Charles Evans Hughes Gold Medal given by the National Conference of Christians and Jews, an organization that devotes itself to promoting brotherhood and combating prejudice and discrimination.

He was presented the medal by former Secretary of State Henry A. Kissinger, who received it in 1973. Reagan noted this, and that Secretary of State Alexander Haig was the recipient in 1980.

"By the way, Al asked me to pass along a short message," Reagan quipped. "He said that he wanted you to know that yours has been a big hat to fill. I think I know what he meant by that and I assure you it's a compliment."