Cardinal Seán P. O’Malley, in a letter to pastors and another to religious superiors, said the campaign is meant to strengthen the vocation of marriage in the Commonwealth. Marriage is “in crisis,” he said, citing statistics that show a decline in marriages in the Archdiocese of Boston from 12,274 weddings in 1986 to 4,519 in 2006.

“Over the past 20 years, there has been more than a 60 percent decline in the number of marriages recorded in the Archdiocese of Boston,” he wrote. “We are concerned also about the well-being of newly married couples and those who have been married for many years.”

The letters outline how recipients can assist in the effort. Priests and religious are encouraged to distribute prayer cards and pray for marriage daily.

Cardinal O’Malley said that the campaign for marriage is not directly related to the marriage amendment, which was defeated on June 14. Planning for the effort began early this year, long before the constitutional convention.

“In light of our state Legislature failing to allow the voters of Massachusetts the opportunity to vote on marriage, we are even more committed, he added.

The Church locally and nationally is attempting to respond to the many challenges facing married couples today. The United States Conference of Catholic Bishops is in the midst of a multi-year National Pastoral Initiative on Marriage. Cardinal O’Malley also established a Committee on Marriage, which began meeting in January of 2006.

“We’ve been concerned about marriage, not just the definition of it,” said Kari Colella, coordinator of marriage ministries for the archdiocese.

“We’re in the process of developing the educational piece, which should be available in the fall,” Colella added.

However, prayer is the foundation and cornerstone of the effort, which begins with the distribution of the prayer cards, she said.

The prayer asks God to help us treasure the self-giving love of husband and wife, support spouses in their vocation and uphold the institution of marriage in society.

“Help us acknowledge that our future depends on this love and on your providential care for us. Amen,” the prayer concludes.

Spanish, Portuguese, Creole and Vietnamese versions of the cards will also be made available, Colella said.

On June 22, a Mass for the vocation of marriage will be offered at Bishop Peterson Hall in Brighton for chancery staff. Father Richard Erikson, vicar general and moderator of the curia, will celebrate the Mass on the feast of St. Thomas More, the patron saint of troubled marriages.

St. Thomas More who was beheaded for his opposition to Henry VIII’s divorce from Catherine of Aragon and subsequent refusal to swear to the Act of Succession in 1534, which declared Catherine’s children first in line for the throne, and the Oath of Supremacy, which recognized Henry VIII as head of the Church of England.

Colella said of St. Thomas More, “He was martyred for the vocation of marriage.”