Archbishop-designate Timothy Dolan urged Americans to swap fear for faith during a prayer service that began his formal installation as New York's Roman Catholic leader.
Dolan, the former Milwaukee archbishop, said the church is "at her best" when inviting others to accept Jesus and turn away from "sin and isolation."
"That's the ultimate question," he told the estimated 1,500 well-wishers in St. Patrick's Cathedral on Tuesday night. "Will we open up in faith, hope and love to the God who gently knocks on the door of our being, asking Him to live with us? Or will fear, self-absorption, and darkness keep us locked up in ourselves?"
The worship service was the first of two ceremonies for Dolan, who succeeds New York Cardinal Edward Egan. The 77-year-old prelate is retiring after nine years. The installation wraps up Wednesday with a Mass in the cathedral.
The Archdiocese of New York is the nation's second-largest diocese after Los Angeles, yet it is the most prominent seat in American Catholicism.
Among Dolan's predecessors was Cardinal Francis Spellman, who was so influential that his residence was dubbed "the powerhouse." Cardinal John O'Connor was the most forceful Catholic voice in the national debates of his era, especially on abortion.
Dolan, 59, is expected to eventually be named a cardinal, as well. He said this week that he will challenge the idea that the church is unenlightened because of its theological opposition to gay marriage and abortion, and hopes to bring alienated Catholics back to regular worship.
The archdiocese covers a region with 2.5 million parishioners in about 400 churches and an annual budget estimated to be at least half a billion dollars.
Its vast Catholic service network includes 10 colleges and universities, hundreds of schools and aid agencies, and nine hospitals that treat about a million people annually.
Dolan faces challenges identical to those for bishops nationwide: drawing more men to the shrinking priesthood; serving a growing number of Latinos and other immigrants; strengthening the finances of Catholic schools and parishes; and boosting the low rate of Mass attendance.
A St. Louis native and the oldest of five children, Dolan is known for putting a friendly face on Catholic orthodoxy. He holds a doctorate from The Catholic University of America and is former rector of the North American College in Rome, considered the West Point for U.S. priests.
In Tuesday's service, Dolan mixed piety and humor, as worshippers stood and cheered for him.
Early in the event, Dolan stood outside the cathedral, grinning broadly and waving to cheering bystanders. As part of the ritual, he knocked on the massive cathedral doors nine consecutive times before entering. A burly man, he said, "Thanks for opening the door wide enough even for me to get in." When he sat in the archbishop's chair for the first time, which was adorned with his episcopal coat of arms, he quipped, "It's very comfortable."
Archbishop Pietro Sambi, the Vatican ambassador to the U.S., read a letter from Pope Benedict XVI naming Dolan to the job.