All people form beliefs in order to understand, survive and give meaning to the world they live in. But where do our beliefs come from and how do they form? To find answers to this age-old question, Dr. Oz talks with Dr. Andrew Newberg, author of Why We Believe What We Believe, about the role that beliefs have in people's lives.

Dr. Newberg, a professor of radiology, psychiatry and religious studies at the University of Pennsylvania, says beliefs are formed by a combination of factors, including our biology, perceptions and social interactions. "All these different ideas and the cognitions that we have, the emotions that we have—all of this comes together to create these stories, these ideas about the world, and those become our beliefs," he says.

On the one hand, Dr. Newberg says that our brains have no choice but to create beliefs—they provide a framework and foundation for how we live and move in the world. On the other hand, he says our beliefs are fundamentally incomplete and subjective because we can never know all the facts. "Unfortunately, a lot of people think, 'Our brain is telling us we have a complete view of the world,' so a lot of us go through the world thinking we know everything," he says.

Dr. Newberg says our beliefs inform our behaviors and vice versa. Recognizing the flaws and limitations of our beliefs, he says, may help individuals avoid beliefs that can lead to negative or harmful behaviors. "I think you can build in some flexibility into that belief system and be a little bit more open and accepting of what other ideas are out there," he says. "That's very valuable."