TOWNSEND — Becoming a priest has been a consideration for Colin McNabb ever since he was a teenager.

At 17, when the calling beckoned, he was too young to enter the seminary. Then life happened. College, and in turn, work, took priority.

In his mid-20s, he began to think about the priesthood once again. But he met the woman who would become his fiancé. They were engaged for six years.

“She’d always ask me if I was thinking of being a priest,” McNabb said. He remained active in his local parish, a regular church-goer and a member of the Knights of Columbus. He attained the highest degree in the Catholic fraternal organization.

When he and his fiancé broke up, McNabb revisited his earlier thoughts. He began the process of applying to seminary in order to become a Catholic priest.

When he was accepted to the seminary, his former fiancé gave him a big hug and told him she really, really loved him, McNabb said.

The process of being accepted into seminary is long and arduous, he said. He began what is called discernment over a year ago. Interviews, retreats and testing were all designed to help him decide if his vocation is the priesthood.

“They know every single thing about your life,” he said.

Applicants need a sponsor, a bishop, to apply to St. John’s Seminary in Boston. McNabb found one in Cardinal Sean O’Malley.

After an interview with a panel of priests, McNabb was accepted in August. He announced his probable resignation from the Board of Selectmen, of which he is chair, on Aug. 11. School starts on Aug. 26.

Soon, politics will be in his past. So too, will his work life in the family business, McNabb Pharmacy. His involvement with the town he loves will greatly decrease. Church rules say he will never be able to be the parish priest in Townsend.

“They won’t put you in your home parish,” he said.

“I worry about Townsend,” he said. He leaves his position as selectman with almost eight months left in his term. “I hope my two colleagues will be careful with any major changes in Townsend. There could be repercussions down the road.”

The Townsend Business Association benefited from his energy as past president.

McNabb will move from his apartment into the men-only seminary on the campus of Boston College. Women, and males under 18, are not allowed in the living quarters.

There, he and the other seminarians will have a busy schedule. Times for meals, classes, masses and prayers are scheduled through the week. Curfew is at 11 p.m.

The Catholic leadership wants its priests to be in good health, and McNabb expects to make some healthy changes. “It’s basically ecclesiastical boot camp,” he said.

Saturdays will bring a little free time, and McNabb plans to visit Townsend to spend time with family.

At age 35, McNabb will be one of the older seminarians at St. John’s. Except for a few men who enter the seminary from another religious order, the students have already attended college. McNabb graduated from the University of Vermont in 2002 with a Bachelor of Arts in political science and a minor in American and Islamic history.

Another Boston seminary specializes in training older men to become priests, but McNabb said he prefers being with the younger group.

After two years of pre-theology and four years of theology studies, McNabb plans to become a diocesan priest. He will serve in parishes in the Boston archdiocese or in other positions as directed by the Boston archdiocese.

The last few weeks of August will be busy for McNabb. Leaving his apartment means getting rid of most of what he has accumulated. There is no need for a sofa in the small, single room he will occupy. He hopes his sister will take his cat.

He is hiring people to do his job at the pharmacy and releasing his ties to the town’s government and business community.

McNabb is excited about the change. His laptop is filled with colorful images of the seminary that he is quick to share with well-wishers who stop in the store.

An element of sorrow is also evident. Not only is he leaving the life he built, he is moving away from his large, extended family and his older parents. Phone calls, emails and weekly visits are all planned.

“You’ve got to go with what God tells you,” McNabb said.

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