For the last 25 years, Pieta has brought together parents who have suffered the tragedy of the loss of a child.

On Dec. 3 Cardinal Seán O’Malley joined the group’s annual candle-lighting service, open to members and non-members, at West Roxbury’s St. Theresa of Avila Church.

“Pieta is an organization that nobody wants to join,” said Barbara Waters, who with Jo Musco Callari, founded the group after their daughters were killed in the same car accident 28 years ago.

When the parents entered the church for the service, they were asked the name of the children they were mourning. Volunteers then wrote the name, and in many cases names, on index cards. Other volunteers passed out thick white candles in clear glass jars to the parents.

When the time came, hundreds of parents emptied the pews and lined up along the left side aisle of the stone church. Each family was asked to send one representative, though some still lined up as couples or with the surviving siblings. As they came forward one-by-one, the card was handed to Father Timothy J. Kelleher, the group’s chaplain, who announced each name, punctuated by the toll of a single hand bell that pieced the air of the silent and darkened church.

As the name was read, the family member holding the candle was directed to a station at the head of the center aisle in front of the altar. There, another volunteer lit the candle and it was brought back to the pews.

The service’s principal celebrant, Bishop John A. Dooher, the bishop for the Southern Region, said when he listened to the more that 325 names he was struck by the quiet in the church and the sacredness of each life. “My God, there are so many of them, and so many more.”

Each life is sacred, as is a parent’s grief and the memory of a lost child, he said.

Despite tears, questions, fears, anger and doubt, it is faith that allows us to hang on, he said.

“It is with hope that we can carry on day-by-day,” he said.

The bishop said it is important to hear Paul’s words on grieving to the Thessalonians, included in the service’s second reading. “I would not have you grieve like those with no hope.”

Because the parents do not grieve alone and they do not remember alone, he said, “Your experience and compassion can heal others,” he said. “What we do here never ends here.”

“Sorrows that are shared are diminished. Joys that are shared are augmented,” said the cardinal in his remarks after the service’s lighting ceremony.

The cardinal said the name of the group comes from Michelangelo’s statue in Rome, which might be the most viewed statue in that city. “It is not only the beauty of the marble, but the emotion of Our Lady as she holds her dead child in her arms.”

It is vital to remember that two days later, Mary was reunited with Jesus, he said. “Today, we remember all of the children who have departed. One day, we will all be reunited.

In the front of the church to the left side of the altar, three long tables were set up with hundreds of poster boards filled with snapshots of the children remembered that night. There were older photos in black and white together with more recent color pictures, including young men in military uniforms.

Next to the tables was a basswood miniature Pieta, carved by Basil LeBlanc, a member of St. Mary’s Parish in Franklin. LeBlanc said although he has not lost a child, he wanted to share the piece with the group that shares the name of the work and to lend something to the service.

Waters is a friend of LeBlanc’s and she said she was very grateful he shared such a beautiful piece of art with the group.

When she spoke at the service, Waters said when a child dies, it is like the parent is left with a cold and dark plot of dirt and an overwhelming sadness. “Tears come from the deepest and purest part of our hearts.”

By coming together on the first Wednesday evening of every month at Walpole’s Blessed Sacrament Church, members of Pieta share tears together that they are never ashamed of shedding, she said.

At the meetings, members are allowed to talk as long as they want, so the parents can learn about each other’s children, she said. “We tell stories--the ones you could not laugh at then, but can laugh at now.”

Pieta members help each other get going again, she said. “All this time, with our pain, our hurt and our anger, we are tilling the ground and watering it with our tears.”

Over time, that barren patch of soil starts to turn green and flourishing, she said. “When we do something in memory of our child that reflects them.”

Since the organization’s founding, parents have made tremendous contributions to their communities by actively cherishing the memory of their children, she said. In this way, each of the parents tends a garden in memory of their child.

One mother, whose daughter was killed by her daughter’s husband has become active in raising money for shelters for battered women and has testified on Beacon Hill on the need for greater protection for victims of domestic abuse.

One father volunteered to help an elderly man after his daughter died, Waters said. The father, in the spirit of his own daughter’s compassion for others, fed the man and cared for him in every way. Before the elderly man died he told someone: “No one has ever washed my feet before.”

Another father, whose son, she said, was killed by a drunk driver, went into the prison where the driver, himself a young man, was incarcerated. That father reached out to the driver in the spirit of forgiveness to lift the burden he was carrying from what he had done.

“God knows and our children know what you are doing in your garden and they are so very proud,” Waters said.