MANCHESTER, N.H. ? Fighting to save his faltering presidential campaign, former Massachusetts Gov. Mitt Romney said Monday that he will reassure Republican voters that his religious values are the same as theirs and that he believes faith has a place in political life and governing.

Rather than hoping that voters will look past his Mormon beliefs, Romney will confront the issue of his faith directly in a speech on Thursday, stressing what he calls a “common heritage” in America that unites people of different religions around a common set of beliefs.

“I’m concerned that faith has disappeared in many respects from the public square,” Romney said at a town hall meeting. “I want to make sure that we maintain our religious heritage in this country – not of a particular brand of faith, if you will, not a particular sect or denomination, but rather the great moral heritage that we have.”

It is a different message from the one John F. Kennedy delivered 47 years ago in what was considered a turning point in his presidential campaign. In that speech, Kennedy sought to save his bid to become the nation’s first Roman Catholic president by promising Americans that he would not mix the religious and the secular or take directions from the pope.

A half-century later, Romney’s audience is as different from Kennedy’s as is his message.

To emerge from a crowded and unsettled field of Republican candidates, Romney must persuade evangelical voters and Christian conservatives that as a Mormon he shares the same moral underpinnings they have, even if the teachings and traditions of the Church of Jesus Christ of Latter-day Saints, as it is officially known, are foreign to them. And he must do it, his top advisers believe, without engaging in a point-by-point theological argument.

Romney said Monday that he will not attempt to be a “spokesman for my faith,” despite the curiosity of many about the church’s distinctive traditions, which are centered around the belief that its founding prophet, Joseph Smith, found golden tablets in upstate New York transcribed with a sacred text and left behind by ancient Israelites who once inhabited America.

“I’m not running for pastor in chief,” he told reporters. Pressed to say more about his speech, Romney smiled broadly and said, “Ahhh, you are just going to have to wait and see.”