President Reagan today promised the U.S. Military Academy's graduating class higher military pay and increased spending on military hardware in a commencement address studded with declarations that America is experiencing a spiritual revival.

For the first time, Reagan indicated that he favors selective pay increases for the military, and he made no mention of the scheduled 5.3 percent July military pay raise, which he apparently is willing to see deferred until October.

Advocates of selective pay increases have argued that they would help the military keep people with the most needed skills at less cost than the customary across-the-board raises. Reagan said such plans are being studied.

Although Reagan supported the July 1 pay raise, it was voted down by the House, and there is no indication that the White House intends to fight for it. As a result, it is most likely to be postponed until October, when it would be added to the 9.1 percent raised scheduled to take effect then. The delay would help Reagan reduce this year's budget deficit.

Turning to what has become one of the dominant themes of his presidency, Reagan said there is a new spirit on the move in the United States. "The era of self-doubt is over. We've stopped looking at our warts and rediscovered how much there is to love in this blessed land," he said.

"There is a spiritual revival going on, a hunger to be once again proud of America, all that it is and all that it can be," the president told the 906 cadets of the academy's 183rd graduating class in Michie Stadium.

In his second speech outside Washington since he was wounded by a would-be assassin's bullet March 30, Reagan referred to the recent past as a time when the military was subjected to a "lack of respect for the uniform."

Reagan attacked critics of the military, saying, "Those shrill voices that would have us believe the defenders of our nation are somehow the enemies of peace are as false as they are shrill."

The president also reiterated his opposition to the draft. Instead of a draft, Reagan said he favors increasing pay and other benefits to make military careers more attractive.

"Last year's pay increase was a step in the right direction, but we are asking for another in the fiscal year that begins Oct. 1," he said. "We are studying proposals for a merit pay system and increased flexibility in personnel practices."

Except for his general promise of White House support for the military, Reagan's speech was a collection of observations, cliches, jokes and praise for the traditions of West Point and its "long gray line."

The president and his senior advisers at one time considered delivering a major foreign policy speech here, but apparently felt the timing for such an address was not right.

Today's speech and his address at the Notre Dame commencement 10 days ago, largely devoted to nostalgia over his experience playing the role of Notre Dame football star George Gipp, were the first speeches Reagan has given since Ken Khachigian, his principal speech writer in the final stage of the presidential campaign and first months of his presidency, left the White House Staff. The chief speech-writing is now vacant.

Although Reagan spoke at length about Gipp at Notre Dame, he made no mention today of the famous West Point graduate he portrayed in the 1940 movie Santa Fe Trail. Reagan was cast as the young George Custer who was still years away from death at the Little Big Horn and not long out of the academy where he had graudated last in the class of 1861.

On a warm, overcast morning, the president was applauded enthusiastically by a crowd of about 26,000, including the 4,109-member cadet corps, families and guests. Reagan was the first president to address a West Point commencement cermony, since President Ford in 1975.

The president linked neglect of national security, erosion of respect for the military, "social experimentation," and increased taxation as elements that contributed to the present "economic crisis."

He also quoted Chinese military philosopher Sun Tzu and George Washington on outmaneuvering one's enemy and on preserving the peace through military strength. "To subdue the enemy without fighting is the acme of skill," Sun Tzu said.

Reagan pledged that in his administration "the argument, if there is any, will be over which weapons, not whether we forsake weaponry for treaties and agreements." He referred to two books by his friend Laurence Beilenson that make a case for a strong military defense. Beilenson, a Los Angeles lawyer, was general counsel of the Screen Actors Guild when Reagan was the union's president.

Reagan presented diplomas to the top 5 percent of the graduating class, which included Michael Meese, whose father, White House counselor Edwin Meese III, watched smiling on the platform and then shook his son's hand.

Reagan remained on the platform as the class, which included 58 women, filed by to receive diplomas. This is the second coed class to be graduated from West Point.

The president left the stadium just before the new graduates threw their white hats into the air in the traditional gesture of these commencements.

Earlier, class president Mark Hogan presented Reagan with a sabre mounted on wood as a gift from the class of 1981, and Reagan joked that he might carry the sword with him when he visits Capitol Hill.

In his speech, however, Reagan said that the government, "reflecting the will of the people," has returned to "our longtime tradition of bipartisanship" on national security and economic issues.