NEW YORK -- He's the head of a worldwide church that has more than billion members, and yet Pope Benedict XVI is wrestling with serious problems: declining congregations, a shrinking clergy and changing attitudes toward church teachings.

At the Vatican, one can feel the enduring power of the papacy.

Tens of thousands of people crowd St. Peter's Square hoping to catch even a glimpse of Pope Benedict. St. Peter's Basilica is packed whenever the Holy Father celebrates Mass, but outside the Vatican's walls, there is debate over the extent of the pope's influence.

Throughout Western Europe, church attendance is declining even in mostly Roman Catholic countries like Spain and Italy.

In the U.S., a recent survey showed the Roman Catholic Church has suffered the steepest losses of any major religion from members who have switched their faiths.

Even some observant Catholics see the pope as a remote figure, reported WNBC.com in New York.

"He doesn't figure much into my daily Catholic faith," one parishioner said.

Conflict rages around the world despite the pontiff's repeated calls for peace.

Still, some Catholic theologians like Dr. Julia Upton of St. John's University in Queens, N.Y., argue the pope's stature and influence remain unique.

"Yes, the pope matters, not just to Catholics," Upton said. "The pope matters to the world. He's probably the one person who is a world leader."

She said the president of the United States is in charge of a powerful country and subsequently gets the aura cast internationally, but the pope has jurisdiction over Catholics in every country they reside.

And despite their shrinking numbers, there are still more than 1 billion Catholics worldwide.

"I don't think his influence comes in any strong way from his ability to enforce what he has to say, but he has to the world's greatest pulpit," said Peter Steinfels, of Fordham University's Center on Religion and Culture. "To the extent that his words can convey a wisdom and a holiness, they can be influential."

But the pontiff does face a more personal challenge following in the footsteps of the wildly popular John Paul II, arguably the most charismatic pope of modern times, and until Benedict, the only pope St. John's University students have ever known.

"When I first started here, that's when Pope John Paul II passed away, and I was able to witness among college students on this campus, and around the world, about how much that affected people," said Derek Hoy, a senior at St. John's.

Some church experts argue it's simply too early to say definitively whether the pope still matters. Pope Benedict has only led the Catholic Church for three years. They said it's like judging a president while he's still in his first term in office.

The pope is trying to influence change throughout the Roman Catholic Church and around the world. Whether he succeeds is something historians will surely debate for years to come.