SOUTH END — With many wearing traditional emerald green to mark the feast of the patron saint of Boston, several hundred people gathered at the Cathedral of the Holy Cross to mark St. Patrick’s Day with a Mass, presided over by Archbishop Seán P. O’Malley.

Massachusetts Governor Mitt Romney and Minister of State for the Irish government Mary Hanafin, who proclaimed the first reading in Irish, as well as other Irish and British government officials, were among the dignitaries in attendance.

“We come together to honor the memory of a man who is our brother in baptism — a monk and a bishop whose life has had a profound effect on Church history and on world history,” Archbishop O’Malley told the congregation during the homily.

“The saints are God’s masterpieces, and in their lives we glimpse something of God’s beauty — His love, His goodness and His strength,” he continued.

“The remarkable great grace that we find in Patrick’s life was the grace to love his enemies and do good to those who persecuted him,” the archbishop stated.

The archbishop went on to recount how the young Patrick first set foot in Ireland after being kidnapped by Irish pirates. For six years, he was forced to tend the sheep of an Irish chieftain named Milchu, until he was finally able to escape “on a boat that was carrying Irish hounds to be sold on the continent.”

“Years later, Patrick returned to Ireland, not to avenge the wrongs that had been done to him, but to share with the Irish people the light of Christ,” said Archbishop O’Malley, noting that Milchu, the slavemaster, “actually committed suicide because he presumed that Patrick had returned to seek revenge and he did not want to suffer humiliation at the hands of a former slave.”

“Patrick’s great act of forgiveness is no doubt the source of the incredible spiritual journey that he brought to his mission,” the archbishop said.

His prior experience as a slave in Ireland marked Patrick’s conversion, the archbishop said. It exposed him to the Irish language, to the druids, to the customs of the Irish people.

“Those years of bondage were a spiritual preparation for Patrick’s mission,” the archbishop declared.

The life of St. Patrick poses “a special challenge to the Irish people — to overcome in our own lives feelings of resentment or prejudice and embrace Christ’s command to love strangers and even our own enemies,” he continued.

“If we only love those who love us, we are not Christians. St. Patrick’s life documents how God brings good out of evil.”

“Patrick said yes to God for a plan in his life, and that yes made a difference in his life and in the life of millions of people who have been influenced by his vocation,” Archbishop O’Malley declared, noting that Patrick’s zeal led thousands of newly baptized Christians to evangelize not only Ireland, but the entire world.

“For a period of 500 years, nearly all the great missionaries of the Western Church were from the so-called pilgrims — the ‘peregrini’ — from Ireland,” he stated. A “peregrinus” was a person who had made a vow of perpetual exile, “to sleep each night in a different place, to travel to the ends of the earth announcing the Gospel of Jesus Christ and the Catholic faith,” he explained.

Because of the crumbling of the Roman Empire, the archbishop noted that “without these Irish missionaries, literacy and books might have disappeared entirely from Europe, along with the Christian faith.”

This missionary spirit continues today, the archbishop went on to say, noting that “on every continent you’ll find Irish missionaries working with the poorest of the poor, announcing the good news of the kingdom.”

“St. Patrick — like all the apostles — did not preach a comfortable Christianity, a feel-good religion with the warm fuzzies,” Archbishop O’Malley stressed. “Patrick, like all, preached Christ crucified, the folly of the cross — that folly which is wiser than the wisdom of man.”

He then went on to affirm that throughout the history of the Irish people, “it’s been that faith that has sustained us in every generation.”

Concluding his homily, he exhorted the assembly, “Today we celebrate the feast of a man who was a true evangelizer — a man transformed by the Gospel and on fire with his desire to share the Good News with others. Patrick’s faith and life for Christ and for His Church made a difference ... May our faith make a difference.”

Following the Mass, everyone was given a potted shamrock, a tradition held by the Archdiocese of Boston for many years.

Speaking after the Mass, Padraig Cantillon-Murphy, 22, a graduate student studying at MIT who is originally from Coachford in County Cork said, “I was very impressed with the Mass, especially having the readings in Irish. It made me feel quite at home.”

He also praised the harpist whose music “was absolutely outstanding.”

Noting that this was his “first Patrick’s day here in the States,” Cantillon-Murphy admitted with a smile that “this was almost better than at home ... almost.”