In stark contrast to comments made earlier this week, Republican presidential candidate Rick Santorum addressed the issue of now-President Barack Obama's Christian faith in a 2008 interview with the Oxford Centre for Religion and Public Life, Buzzfeed reported Tuesday.

When asked if he believed Obama is a "sincere liberal Christian," the former Pennsylvania senator said he didn't believe that sort of ideology exists, and that Obama's church, United Church of Christ in Chicago, had "abandoned Christendom" and used a non-literal interpretation of the Bible.

"I don't think there is such a thing," he said of Obama as a liberal Christian. "To take what is plainly written and say that 'I don't agree with that, therefore I don't have to pay attention to it,' means you're not what you say you are. You're a liberal something, but you're not a Christian."

Santorum made headlines last week after telling an Ohio crowd that Obama subscribes to "some phony theology, not a theology based on the Bible."

He defended his comments on Sunday during an interview with CBS News' "Face the Nation."

"I've repeatedly said I don't question the president's faith," he said. "I've repeatedly said that I believe the president's Christian."

He further clarified, "I am talking about his worldview or the way he approaches problems in this country and I think they're different than how most people do in America."

However, Santorum has continued to criticize Obama on matters of faith. On Monday, he told a Michigan audience that Obama was "particularly weak" in protecting religious liberty.

"When you have the president of the United States referring to the freedom of religion and you have the Secretary of State referring to the freedom of religion, not as the freedom of religion but the freedom of worship, you should get very nervous, very nervous," he said.