Now those early church lessons of determination are on display as Mr. Romney, already a two-time Republican presidential candidate and his party’s 2012 nominee, contemplates another run.

Friends and former advisers say Mr. Romney does not believe he was divinely called to seek the presidency a third time, and is chiefly motivated by his concern over the direction of the country.

But many close to him also point to the perseverance he learned as a missionary; the sense of American exceptionalism and public service central to the church’s teachings; and his belief — buttressed by his faith — that if he feels in his heart he has something to offer the country, he is compelled to pursue it, regardless of the obstacles.

“There is something not only with his experience in the church, but with his family’s experience in the church back to the Mormon pioneer days — and the church ethos as a whole does inform his thinking and character and behavior,” said Philip Barlow, a professor of Mormon history at Utah State University who served with him in church.

Richard Marriott, an heir to the hotel fortune, a prominent Mormon and a generous supporter of Mr. Romney’s previous campaigns, said that there was no question that Mr. Romney was animated by religion. “Our church tells us clearly that when we are in the service of our fellow man, we are in the service of our God,” he said.

Mr. Romney’s persistence — so baffling to some — is a natural extension of that faith, Mr. Marriott said. “You have to have a dedication to serving others to be able to withstand the battering you get when running for national office,” he said.

The Romney family has repeatedly turned to both God and the church when seeking guidance for political decisions. As early as 2005, the Mormon magazine Sunstone first reported, Mr. Romney began consulting the then-prophet of the Mormon Church, Gordon B. Hinckley, about seeking the presidency. Mr. Hinckley ultimately told him that it was not the church’s decision to make — but some Mormons saw Mr. Romney’s repeated visits as his wanting the church’s private blessing.