In a liturgy rich with symbols and promises, Pope Benedict XVI formally began his ministry as head of the universal church, and Catholics from around the world pledged their love and obedience to him.

The morning of April 24, Pope Benedict, elected April 19, walked down to the tomb of the martyred St. Peter in the Vatican basilica to pay homage to the first bishop of Rome.

Then, with some 150 cardinals, he processed into a sun-bathed St. Peter’s Square to begin the Mass and receive the main symbols of his office: the fisherman’s ring and the pallium.

“At this moment, weak servant of God that I am, I must assume this enormous task, which truly exceeds all human capacity,” Pope Benedict said in his homily.

The 78-year-old pope said he would rely on the prayers of all Catholics and the grace of God.

“I do not have to carry alone what in truth I could never carry alone,” he said.

The new pope said his inaugural Mass was not the moment to present “a program of governance,” but rather a time to promise to try be a good shepherd to Christ’s flock, to rescue those who are lost, to help the poor and to build unity among all believers in Christ.

An estimated 350,000 people attended the Mass, including delegations from more than 130 countries and from dozens of Orthodox, Anglican and Protestant churches.

Florida Gov. Jeb Bush, brother of U.S. President George W. Bush, led the five-member U.S. national delegation. Canada’s governor general, Adrienne Clarkson, led the five-member Canadian delegation.

The German-born pope’s 81-year old brother, Father Georg Ratzinger, was seated in the front row by the altar, not far from German Chancellor Gerhard Schroeder and President Horst Koehler.

The crowd was dotted by faithful waving flags, especially German flags.

Italian President Carlo Azeglio Ciampi, King Juan Carlos of Spain and Britain’s Prince Philip were seated alongside the altar.

Religious calendars created some complications for some delegations. Israel was represented by its ambassador to the Vatican, although the inauguration took place on the first full day of the week-long Passover observance. Sixteen Orthodox churches sent representatives even though April 24 was Palm Sunday on the Julian calendar most of them follow.

Chilean Cardinal Jorge Medina Estevez placed the pallium, a long woolen stole, around the neck of Pope Benedict, reminding him that Jesus has entrusted him with taking up the ministry of St. Peter to shepherd Christ’s flock.

Italian Cardinal Angelo Sodano, Vatican secretary of state, handed Pope Benedict the fisherman’s ring, which the new pope placed on the ring finger of his right hand.

Cardinal Sodano prayed that “the Spirit of love” would fill the new pope with the strength and meekness needed to minister to Christians “in the unity of communion.”

After he received the symbols of his office, Pope Benedict received the act of obedience of his new flock, symbolized by 12 people from eight countries.

Bishop Andrea Erba of Velletri-Segni, who represented diocesan bishops, leads the diocese of which the former Cardinal Joseph Ratzinger was titular head while serving as dean of the College of Cardinals.

Father Enrico Pomili, representing all priests, is pastor of the Rome parish of Santa Maria Consolatrice, Cardinal Ratzinger’s titular church until he became dean of the college in 2002.

The others included a transitional deacon from Africa; a Discalced Carmelite priest who serves as a consultant to the Congregation for the Doctrine of the Faith; a Benedictine abbess; a Korean married couple; a young woman from Sri Lanka; and a young man from Congo.

Italian Cardinal Angelo Sodano, South Korean Cardinal Stephen Kim Sou-hwan and Cardinal Medina represented the College of Cardinals.

Among the thousands of people who gathered in St. Peter’s Square and filled the surrounding streets for the Mass were many who felt represented by the 12.

Francisco Navarro, 36, of Los Angeles said he was not disappointed the world’s cardinals chose a German instead of a Spanish or Latin American pope.

“The pope is the pope,” he said. “I’m happy with it. I hope God will guide him. We feel blessed to be here, to be as one: no racism, no nothing.”

Petra Keller, 36, who is German but lives in Rome, said: “We are proud, yes, but Germans generally are never proud of their country because of their history. They are more proud of where he is from, in Bavaria.”

Keller said that in general: “Germans are very critical. They are waiting to see what he is like because he seems to be very conservative.”

Barbara Schwartzenberg, 49, of Baton Rouge, La., said, “It is nice we have another non-Italian pope to show the universality of the church.”

While the Gospel was chanted in Latin and Greek, the other Bible readings were in English and Spanish. The prayers of the faithful were recited in German, French, Arabic, Chinese and Portuguese.

In French, the people prayed: “For our Holy Father Benedict XVI, who today begins his ministry as the Roman pontiff, may he serve the church and be a courageous witness of the Gospel.”

The bread and wine consecrated by Pope Benedict during the Mass were brought up to him by Catholics from Hungary, Croatia, Kenya, Burkina Faso, Italy, China and Peru; many in the procession wore their national costumes.

During the offertory procession and the act of obedience, Pope Benedict smiled broadly, listened attentively, stroked the cheeks of the young and offered his blessing.

At the end of the Mass, Pope Benedict took his first ride in the popemobile, standing in the back of the open vehicle, waving to the crowd and blessing them with his right hand, newly weighted by the fisherman’s ring.

He then went into St. Peter’s Basilica where a chair was set on an oriental rug before the main altar. Members of the government delegations were led into the basilica to greet him and pose for photographs.

Pope Benedict was to meet April 25 with the delegations from the other Christian churches and from other religions. A separate audience was planned for Catholic pilgrims from Germany.