MIAMI, SEPT. 10 -- As Pope John Paul II stepped into the sanctuary of St. Martha's Roman Catholic Church, a young American priest named Rolando Garcia stood on tiptoes to catch a glimpse of his face. Standing against a wall about 100 feet from the pope, he had to peer through and over a sea of black suits. He couldn't stop smiling.

Ordained only 1 1/2 years ago, the Cuban-born Garcia is exuberant about his calling in the way only novices can be. Today he was enjoying what one priest called a "top-of-the-mountain moment," having not experienced many of the problems that brought 750 priests to this historic meeting with the pope.

Hours before the meeting, Garcia had been asked at the last minute to celebrate a morning Mass for hundreds of other men of the cloth staying at the Biscayne Bay Marriott, otherwise known as "the priests' hotel." He donned a white robe and calmly greeted the men, many old enough to be his father. His sweaty palms were the only evidence of his nervousness.

"Since I've become a priest," he said later with a shrug, "I know I have to be prepared for anything."

Indeed he does. For Garcia, 28, is one of 53,000 U.S. priests whose numbers are predicted to dwindle by half by the end of this century. The shortage of priests hasn't yet taken the toll on Garcia that it has on his older colleagues.

But he worries about it, and so he listened closely at St. Martha's in the late afternoon as fellow priest Frank J. McNulty spoke to the pope about issues that have caused many of his colleagues to resign from the priesthood and persuaded other, younger men to not even give it a try.

"These recent years have not been easy for priests," McNulty, a counselor to priests in suburban New Jersey, said in the speech interrupted 14 times by the applause of his peers. McNulty asked John Paul II to try to understand the issues that he said take American priests to "the top of the mountain" and through "the valleys of darkness."

Also in the St. Martha's audience was an early mentor of Garcia, the Rev. Julio Alvarez-Garcia, who listened with a somewhat more sanguine ear. At 43, Alvarez-Garcia, one of two priests sent to the meeting from the Washington Archdiocese, has experienced more of the valleys than has his younger friend.

These days, he said, those valleys loom large when priests are asked to do too many jobs for too little reward -- serving more than one parish or, in his case, two ethnic communities, Anglo and Hispanic.

"Sometimes I feel that people do not see the many things you are doing," said Alvarez-Garcia, assistant pastor at St. Catherine Catholic Church in Silver Spring. "That's when you sit down and feel sorry for yourself. I do that every 30 minutes or so."

The Rev. Joseph Ranieri, a priest from Lanham sitting next to Alvarez-Garcia, nodded in agreement. The stress of the priesthood weighs heavily on him. He is approaching 55 and thinks about the three priests in their 50s from the Archdiocese who have died since January.

With not enough priests to go around, he said, being a pastor is like "being a plant manager with less personnel, precisely when the plant is at full press."

John Paul II, in response to McNulty's remark, acknowledged that "much is asked of us by many people." Then, as is his wont, he directed the priests back to the roots of their faith -- especially to the Gospel, the sacraments and prayer.

In unison, the priests later began singing the traditional "Heal, Holy Queen" and, as the pontiff left the church, many of them climbed over pews and over each other in an effort to touch him.

Rolando Garcia was among those who wanted just one more look. As a relatively recent arrival from Havana, where the church is discouraged, he finds that the church is still new and magic to him, he said. He said he did not make his first communion until he was 16, the year he arrived in the United States.

Yes, he has to work six days a week -- "Monday is my day to go to the beach." Yes, he gave up his freedom at an early age, "and I had a little trouble with my mother about leaving home."

But when he starts feeling depressed, he said, he recalls his confirmation in the Catholic Church, which happened a year after his first communion.

"The archbishop asked a bunch of us who wanted to become a priest or sister," Garcia recalled. "I looked around, and no one was putting up his hand. So I did, and a great peace came over me."