NEW YORK — Using the historic Saint Patrick's Cathedral structure as an analogy for the strength and purpose of those called to serve their church, Pope Benedict XVI held a Mass Saturday for religious leaders from across the nation.

An estimated 3,000 deacons, priests and other religious officials from nearly every archdiocese gathered for the Mass and heard words of encouragement and support from their Holy Father.

The pope will celebrate another Mass today for 65,000 worshippers at Yankee Stadium.

"The unity of a Gothic cathedral, as we know, is not the static unity of a classical temple, but a unity born of the dynamic tension of diverse forces which impel the architecture upward, pointing it to heaven," the pope said.

"We can see a symbol of the church's unity, which is the unity — as Saint Paul has told us — of a living body composed of many different members, each with its own role and purpose."

The pope compared the cathedral's stained glass windows that look dark from the outside of the church but bright and colorful inside to those who work for the church.

"It is only from the the inside, from the experience of faith and ecclesial life, that we see the church as she truly is: flooded with grace, resplendent in beauty, adorned by the manifolds of the spirit," he said. "It follows that we, who live the life of grace within the church's communion, are called to draw all people into this mystery of light."

For those outside the church, which is across the street from Rockefeller Center, the normally crowded Fifth Avenue was eerily quiet early Saturday morning as the blocked-off streets stopped the humming flow of taxis, limos, buses and cars.

The street may have been empty, but the devoted not lucky enough to be invited to the Mass jammed the surrounding sidewalks for a glimpse of the pope. Two jumbo television screens and large speakers broadcast the Mass as it happened. Spectators knelt on the sidewalk during the consecration of the Eucharist, offered each other the handshake of peace and some on the steps of the Cathedral received Communion.

Nuns from numerous orders, identified by their different styles of veil and habit, along with priests, seminarians deacons and countless others, lined the street in a rainbow of religious vestments. School groups and others also peppered the crowd holding official Pope Benedict visit signs or those created at home.

To pass the time before the pope's arrival, the crowd sang hymns, some in Spanish. Students from Ave Maria University chanted "Ben-ne-dict-to!" while clapping, creating a holy pep rally atmosphere on the cathedral steps.

The odd combination of buzzing helicopters overhead and choral music flowing from the church alerted the crowd the time had arrived, and it burst into thunderous cheers and applause as the pope got out of his black limo.