President Obama's prayers for a strong first debate may not have been answered, but that doesn't mean the prayers weren't happening.

Before he stepped onto a Colorado stage earlier this month to face off with Mitt Romney for the first time, Obama joined a conference call with a small circle of Christian ministers.

"The focus of that prayer was, 'Oh, Lord, you know precisely what the president needs to say,'" says Kirbyjon Caldwell, a Methodist megachurch pastor from Texas who helped lead the call. "'You know what this country needs during the next four years.'"

"'And so I would pray that your primary will and words that you want the president to say will fall from his lips,'" Caldwell goes on, recalling his prayer.

Obama, for his part, was mostly silent.

"There's a profound and genuine humility in the presence of Christ himself," Caldwell says, describing the president on such calls. "I think he recognizes it as a holy moment."

It was the second time Caldwell and Obama had prayed by phone in as many months. The two had connected in August on a prayer call Obama has hosted on his birthday every year since coming to the White House.

Welcome to the intense, out-of-the-box and widely misunderstood religious life of President Barack Obama.

Though he famously left his controversial pastor, the Rev. Jeremiah Wright, the year he was elected to the presidency, a handful of spiritual advisers close to Obama say that his time in office has significantly deepened his faith.

Stephen Mansfield, a former Christian pastor who wrote the book "The Faith of Barack Obama," goes so far to say that Obama has experienced a spiritual transformation.

"I think we do have at heart a new man, so to speak," says Mansfield, who worked closely with the White House and with some Obama religious advisers on his book. "He has undergone a pretty significant personal religious change in his first term."

Obama's faith advisers say Mansfield goes a step too far, though they acknowledge that when it comes to his faith, Obama has changed.

"There is a deepening development in his relationship with God," says Joel Hunter, a Florida-based pastor who has been in touch with Obama nearly every week since he took office. "He chooses to stay faithful in daily habits of study and prayer and consistent times of interchange with spiritual leaders."

"I am not sure he did that before he came to the presidency."

Whether or not Obama has been spiritually "reborn" in the evangelical sense, his spiritual counselors say the president's faith has helped shape his first term in ways that haven't been appreciated by voters or the news media.

And they say the presidency is bringing Obama to a new place in his faith -- building on a system of belief and practice that helped bring him to the White House in the first place.

Talking like Billy Graham

These days, when the president talks about his faith, he sounds like a born-again Christian.

Addressing the National Prayer Breakfast in Washington this year, Obama recalled meeting the nation's most iconic evangelical Christian, Billy Graham, and described his struggle to find the right words as he prayed aloud with the aging evangelist.

"Like that verse in Romans, the Holy Spirit interceded when I didn't know quite what to say," Obama told the gathering, invoking the New Testament.

It was hardly the only part of the speech where Obama was speaking "Christianese" -- employing a lexicon familiar to evangelical Christians, who put a premium on quoting Scripture and communing directly with the Holy Spirit.

At the same breakfast, Obama spoke of spending time every morning in "Scripture and devotion" and dropped the names of "friends like Joel Hunter or T.D. Jakes," both well-known pastors of evangelical megachurches.

"He was talking like Billy Graham" at the breakfast, says Mansfield, who also wrote an admiring spiritual biography of former President George W. Bush.

Even in the more secular setting of the Democratic National Convention, Obama hinted at an intense White House prayer life, along with his need for God's grace.

"While I'm proud of what we've achieved together, I'm far more mindful of my own failings," Obama said in his acceptance speech, "knowing exactly what Lincoln meant when he said, 'I have been driven to my knees many times by the overwhelming conviction that I had no place else to go.'"