It's the holiday season, where many of us engage in religious holidays and festivals. But can we celebrate Diwali, Christmas or Hanukkah if we don't believe in supernatural forces (or Santa Claus)? Why is belief in a god or gods so common throughout history and across cultures? What role does god and religion play in providing meaning in our lives?

From hoop earrings to yoga to rock and roll, people from one culture often "appropriate" elements from other cultures. But is this a case of exploitation? Should people ask permission before drawing from another culture? Are there times when another culture is off limits?