(RNS) In recent days, GOP presidential candidate Rick Santorum has criticized President Obama for having a "phony theology" not based on the Bible, and prominent evangelist Franklin Graham has said he does not know if Obama is a Christian.

“You have to ask him. I cannot answer that question for anybody," Graham said Tuesday (Feb. 21) on the MSNBC program "Morning Joe." On the other hand, Graham said that he believes Santorum is a Christian because "his values are so clear on moral issues." 

Even as a significant percentage of Americans falsely believe Obama is Muslim, the president has spoken of his Christian faith with increasing fervor during his three years in the White House. 

Here's a sample, in reverse chronological order, of five of Obama's most personal statements on Christianity:

From the Christmas Tree lighting ceremony in Washington on Dec. 2, 2011

"More than 2,000 years ago, a child was born to two faithful travelers who could find rest only in a stable, among the cattle and the sheep. But this was not just any child. Christ’s birth made the angels rejoice and attracted shepherds and kings from afar. He was a manifestation of God’s love for us.

"And he grew up to become a leader with a servant’s heart who taught us a message as simple as it is powerful: that we should love God, and love our neighbor as ourselves. That teaching has come to encircle the globe. No matter who we are, or where we come from, or how we worship, it’s a message that can unite all of us on this holiday season."

From an Easter Prayer Breakfast on April 19, 2011 at the White House

"I wanted to host this breakfast for a simple reason -– because as busy as we are, as many tasks as pile up, during this season, we are reminded that there’s something about the resurrection -- something about the resurrection of our savior, Jesus Christ, that puts everything else in perspective.

"We all live in the hustle and bustle of our work.  And everybody in this room has weighty responsibilities, from leading churches and denominations, to helping to administer important government programs, to shaping our culture in various ways.  And I admit that my plate has been full as well.  The inbox keeps on accumulating. 

"But then comes Holy Week.  The triumph of Palm Sunday.  The humility of Jesus washing the disciples’ feet.  His slow march up that hill, and the pain and the scorn and the shame of the cross. And we’re reminded that in that moment, he took on the sins of the world -- past, present and future -- and he extended to us that unfathomable gift of grace and salvation through his death and resurrection."

From the National Prayer Breakfast on Feb. 3, 2011

"And like all of us, my faith journey has had its twists and turns. It hasn’t always been a straight line. I have thanked God for the joys of parenthood and Michelle’s willingness to put up with me. In the wake of failures and disappointments I've questioned what God had in store for me and been reminded that God’s plans for us may not always match our own short-sighted desires.

"And let me tell you, these past two years, they have deepened my faith. The presidency has a funny way of making a person feel the need to pray. Abe Lincoln said, as many of you know, 'I have been driven to my knees many times by the overwhelming conviction that I had no place else to go.'"

From an Easter Prayer Breakfast on April 6, 2010 at the White House

"For even after the passage of 2,000 years, we can still picture the moment in our mind’s eye. The young man from Nazareth marched through Jerusalem; object of scorn and derision and abuse and torture by an empire.  The agony of crucifixion amid the cries of thieves.  The discovery, just three days later, that would forever alter our world -- that the Son of Man was not to be found in his tomb and that Jesus Christ had risen.

"We are awed by the grace he showed even to those who would have killed him.  We are thankful for the sacrifice he gave for the sins of humanity.  And we glory in the promise of redemption in the resurrection."

From the National Prayer Breakfast on Feb. 6, 2009 

"I was not raised in a particularly religious household. I had a father who was born a Muslim but became an atheist, grandparents who were non-practicing Methodists and Baptists, and a mother who was skeptical of organized religion, even as she was the kindest, most spiritual person I’ve ever known. She was the one who taught me as a child to love, and to understand, and to do unto others as I would want done.

"I didn’t become a Christian until many years later, when I moved to the South Side of Chicago after college. It happened not because of indoctrination or a sudden revelation, but because I spent month after month working with church folks who simply wanted to help neighbors who were down on their luck – no matter what they looked like, or where they came from, or who they prayed to. It was on those streets, in those neighborhoods, that I first heard God’s spirit beckon me. It was there that I felt called to a higher purpose – his purpose."