ALBUQUERQUE, N.M. » President Barack Obama, in a rare discussion about his religious beliefs, described himself yesterday as a "Christian by choice" who arrived at his faith in adulthood because "the precepts of Jesus Christ" helped him envision the kind of life he wanted to lead.

Obama talked about his beliefs when he was asked, "Why are you a Christian?" The question was posed by a woman at a backyard conversation here, part of a series of meetings Obama is holding to talk informally with Americans.

Some conservatives and political opponents have questioned Obama’s Christian faith. In fact, a Pew Research Center poll in August found that 18 percent of people wrongly believe Obama is Muslim — up from 11 percent who said so in March 2009. Just 34 percent said they thought Obama is Christian.

"I’m a Christian by choice," Obama told his audience here. "My family didn’t — frankly, they weren’t folks who went to church every week. And my mother was one of the most spiritual people I knew, but she didn’t raise me in the church.

"So I came to my Christian faith later in life."

"I think also understanding that Jesus Christ dying for my sins spoke to the humility we all have to have as human beings, that we’re sinful and we’re flawed and we make mistakes, and that we achieve salvation through the grace of God," Obama said. "But what we can do, as flawed as we are, is still see God in other people and do our best to help them find their own grace."

Obama said he seeks to do that through daily prayer and public service. "That’s what I strive to do. That’s what I pray to do every day," he said. "I think my public service is part of that effort to express my Christian faith."