WASHINGTON — President Barack Obama is getting more public about his Christianity.

First he raised his Christian faith at a White House news conference last month. Then he went church for the first time in five months. And on Tuesday he responded to a question with an expansive talk about how Jesus Christ influences his life and how he prays daily.

These public displays of his religion mark a change from the first year and a half of his presidency, when he kept his faith a largely private matter — and they come after a poll found a growing number of Americans mistakenly think he's a Muslim, or don't know his religion.

"He does seem to be talking about his faith more," said John Green, a political scientist at the University of Akron and a senior fellow at the Pew Forum on Religion and Public Life. "That is a contrast to the previous 18 months where he hardly talked about it at all."

"It stands out because he's not been overtly religious," said Dennis Goldford, a political scientist at Drake University in Iowa.

Obama has been a man without a regular church ever since he resigned from the Trinity United Church of Christ in Chicago in 2008. Obama's membership in that church had become a political embarrassment after videos came to light showing racially inflammatory and anti-American sermons by pastor and Obama friend the Rev. Jeremiah Wright.

Obama has not joined a church in Washington and rarely attends services, saying he doesn't want to disrupt the congregations. He does consult with pastors personally, but has shied away from public discussions of his faith.