BOSTON – In the back office of his Weston, Mass., headquarters a quarter-century ago, Mitt Romney, the chief Mormon authority in the Boston area, told the leader of his Spanish-speaking congregation that he would not directly pay for lawyers to help the growing number of illegal immigrants in his church.

Then he carefully instructed his subordinate on how to circumvent the Mormon church’s new hard line against such assistance and subsidize their legal aide.

“In those issues I cannot help you financially to pay for lawyers,” Romney said, according to Jose Francisco Anleu, a Guatemalan immigrant. “But what I can do is allow you to give them food assistance from the bishop’s warehouse,” a church welfare pantry. The money saved could be used to “pay lawyers.”

He reminded Anleu that he could use church funds to cover rent, utilities and health care for his needy members.

Romney’s decades as a lay church leader – first as bishop and later as stake president, which gave him dominion over all the churches in and around Boston – shaped a man as orthodox and committed to his faith as any presidential nominee in history. It is an experience that demonstrates Romney’s mastery of the institution and confidence in his authority.

On Sunday, Romney, who often goes to Mormon services when on the road, read Scriptures from an iPad, received the sacrament of white bread and water and sang hymns with his family as he attended church near his lake house in New Hampshire. And for the first time since becoming a presidential candidate, he invited the media to watch.

But in the largely invisible universe of his church, Romney consistently acted as a community organizer with a genius for milking hours out of the workweek and talent from his aides. He wept with spiritual fervor and believed in a traditional brand of Mormonism that sought daily divine intervention, according to many of his fellow churchgoers. But he also favored tangible action over introspection and told Patrick Graham, a confidant at Bain and Co., that he planned to give half his money to the church.

Romney’s church service in the 1970s – when he served as a bishop’s assistant, a religion teacher to teenagers and a networking member of a council of church elders – put him in a position, at the relatively young age of 34, to answer the calling of bishop. As bishop, Romney held his flock to a high standard. He expected congregants to fill out the Tithing and Other Offerings slips available outside his office. He determined who could and could not carry a “recommend,” a physical card that serves as proof of a person’s doctrinal standing and suitability to enter the sacred temples.

Nolan Don Archibal, a former member of the Cambridge congregation who went on to become executive chairman of the board at Stanley Black & Decker, said Romney picked up the phone to help the unemployed members of his congregation find work. He acted as a marriage counselor and a mentor to troubled teens and provided a willing ear to lonely widows. He called on those in his flock struggling with a crisis in faith to publicly meditate on their problems at sacrament meetings.

On one occasion, he dropped off Phil Barlow, one of his counselors, at his home and the two discussed the array of challenges their congregation faced.

“The one that bothers me the most that I’ve thought a lot about over the years,” Romney told Barlow, “is how genuinely to help the poor.”

Romney’s authority as stake president over the thousands of Mormons in the Boston area was near absolute. He gradually shed his reputation as an enforcer of the doctrine of the faith. He compromised with the Mormon feminists who wanted more speaking roles and recognition of accomplishments in the church and commanded his bishops to root out domestic abuse in their wards, according to several women who witnessed Romney’s progression.