This is the fourth in a series of articles profiling each of the nine men who will be ordained to the priesthood by Cardinal Seán P. O'Malley at the Cathedral of the Holy Cross on May 21. Earlier articles in the series are available at TheBostonPilot.com.

BRIGHTON -- Deacon Thomas Sullivan has lived his life surrounded by clergy. One paternal uncle is a permanent deacon; another is a Josephite priest. His paternal aunt is a sister of the Blessed Sacrament. He also has two great uncles who are priests -- one is a Redemptorist Father, the other a Passionist Father.

"You can kind of say vocations run in my family," he said with a smile.

"That being the atmosphere I grew up in, religious vocations was never something that seemed like an impossibility," he said.

Although he cannot pinpoint the exact moment he felt called to the priesthood, Deacon Sullivan does recall sitting in the pews at St. Theresa of the Child Jesus in Watertown thinking to himself, "I could do that."

"I am very lucky that I come from a faithful family," he said. "Priests and religious didn't seem to me to be people up on pedestals, they were all just my uncles."

Deacon Sullivan attended Boston College High School, graduating in 2000. Four years later, he graduated with a philosophy degree from Boston College, always convinced that one day he would enter the seminary.

"After graduating, I kind of put it off for a while though," he admitted. For several years, Deacon Sullivan worked at his uncle's hardware store, until in 2011 he applied to St. John Seminary in Brighton under the guidance of Father Charles Higgins, pastor of Mary Immaculate of Lourdes parish in Newton.

"To be able to have come from a good family, a faithful family and a loving family, and also a family that has always practiced the faith has set me on this course," he said.

On Aug. 4, 2011, the feast day of St. John Vianney, Deacon Sullivan entered St. John Seminary. His parents and older sister, though very supportive, were not at all surprised.

Deacon Sullivan noted that his is the only vocation from among his cousins. "So now the next generation has to come up with one," he joked.

Once at St. John Seminary, Deacon Sullivan developed many close friendships among his fellow seminarians, something he says he will miss once he is ordained.

"Having your friends living in the same place as you has been great," he said.

He also praised the formators and professors he has had over the years.

"I've always enjoyed school," Deacon Sullivan said, "and to be able to focus in a special way on theology and the faith has been great."

"The great teachers here have been instrumental in strengthening and forming my faith, as well as helping me in my prayer life," he continued.

As a deacon, he has been assigned to St. Thomas Aquinas Parish in Bridgewater.

"I have loved applying my studies and prayer to ministry," he said. "To be able to share what I've benefitted from the seminary to the people in the parish has been great."

He looks forward to celebrating Mass and hearing confessions once he is ordained.

"It has been so important to me in my life -- not just as a seminarian or as one with an eye to the vocation. To me, the sacraments are totally indispensible," he said.

He acknowledges that there are challenges ahead.

"Christian living is a challenge in and of itself, but Christ gives us what we need that we can live the life he calls us to, both now and in the world to come. But there's also the challenge of reaching out to people who are away, connecting them once again to the sacramental life of the Church, which they may not know they need but they do need," he said.

"As a priest, there's also the challenge of making sure that you remember that you are one of those people who need God too," he continued. "Not to lose sight of the fact that you need to take care of your own spiritual well-being when you're out there tending to others."

But Deacon Sullivan is ready to take on the challenges ahead.

"The most formative things in my life have been family and faith," he mused. "The natural foundation of family and the supernatural foundation that the sacramental life of the Church gives me: that's what has made me, for better or worse," he laughed. "I'm ready."