Graham, the son of Billy Graham and president of the charity Samaritan's Purse, responded to criticism from a black clergy group that is part of the National Association for the Advancement of Colored People, Religious News Service reported. In a statement, the group accused Graham of bearing "false witness."
"I regret any comments I have ever made which may have cast any doubt on the personal faith of our president, Mr. Obama," Graham said in a statement Tuesday. "I apologize to him and to any I have offended for not better articulating my reason for not supporting him in this election -- for his faith has nothing to do with my consideration of him as a candidate."
He added that he considers Obama's support for abortion rights and his stand on same-sex marriage to violate scripture.
In an interview on MSNBC, Graham said he could not "answer that question for anybody" when he was asked if he believes Obama is a Christian. He then said that under Islamic law Obama would be a Muslim because his father was one.