BOSTON -- For more than a decade, Walter Osterman Jr. has been on a journey of faith -- one to attend Mass at every one of the 55 Catholic churches in the city of Boston.Osterman, 54, grew up in New York but has lived in Massachusetts, where his wife is from, for almost 20 years. He and his family are active members of Holy Mothers Collaborative in Hanover. He is the president and CEO of Social Mavens, a marketing and communications agency in Hingham that represents many faith-based clients.

He got the idea to visit all the Catholic churches of Boston from his father, Walter Osterman Sr., who, years ago, decided to attend Mass at each of the 105 Catholic churches in Manhattan that existed at the time.

While his father had relied on a phonebook for guidance, Osterman compiled his list of Boston churches from the directory on the archdiocese's website.

Beginning around 2008, he tried to plan his Mass attendance by neighborhood, starting with South Boston and ending with the Back Bay. He always went to Sunday Mass but sometimes also attended daily Mass during the week.

"As a New Yorker, I wasn't, at the time, that familiar with Boston. So it was a really interesting way to learn all the neighborhoods," Osterman said in a Jan. 31 interview with The Pilot.

Sometimes he took friends or family members with him on his visits to different churches. He brought his father-in-law, who was born in Sicily, to St. Stephen Church in the North End. Osterman's father, who now lives in an assisted living facility on Cape Cod, sometimes accompanied him when visiting on weekends.

"From Chinatown to Hyde Park to Jamaica Plain, each neighborhood was a new adventure and each had so much to offer. I enjoyed every minute of my travels," Osterman said in an email shared with The Pilot.

What struck Osterman the most was how kind the priests and parishioners were to him. People could usually tell that he was not a member of their parish. His presence as a newcomer was especially noticeable when he attended daily Mass on weekdays, which drew smaller numbers of worshipers than Sunday Mass.

There was one memorable exception to this: at one Mass, a visiting priest invited Osterman to serve as a lector.

"It was great to see the faces of the people in the pews when I walked up to the lectern," he said.

On another occasion, Osterman and his father happened to visit St. Angela Merici Parish in Mattapan, which has a large Haitian community, the Sunday after the devastating 2010 earthquake in Haiti. They did not anticipate the great number of grieving Haitian-Americans who attended that weekend. But even in those circumstances, they received a warm welcome -- at the Sign of Peace, parishioners got out of their pews to greet them. Osterman said that Mass was "the most impactful."

"There are all these great people and all these great neighborhoods, they're really nice and really kind, they belong to these beautiful churches. And that's what I got to experience," Osterman said.

He usually sat in the back, in order to better take in each church and its people. He said it is "impossible" to say which church was his favorite, but he named a few that stood out. When he visited St. Peter Parish in Dorchester, the Mass was held in the basement, but afterwards the priest showed Osterman the sanctuary upstairs. He found the stained glass windows of Holy Family Church in Dorchester "breathtaking," and that stepping into St. Clement Eucharistic Shrine filled him with "an incredible sense of peace and calmness."

He visited the final church on his list, the Lourdes Center, just outside Kenmore Square, on Jan. 11.

"I was happy, but I was sad, too. But it was neat to do it for my dad while he was still alive, so (he) can see that we did it together," Osterman said.

Though he does not plan to do it over again, he said there are many churches that he will revisit.

When asked if he would recommend the experience, Osterman answered, "Absolutely."

"There's so much more to our faith than our little one parish. This was just one tiny way of branching out so you can see all the people and how they pray and how they worship and how kind they were," Osterman said.