Why is religion important to Pi and how does it help him survive?
In order to survive his ordeal at sea, Pi called upon his beliefs from a number of different religious beliefs, including the lack of belief in atheism. The religions that he relied upon include Hinduism, Christianity, Islam, and Atheism. Pi prayed three times a day: morning, noon, and night, thus placing his survival in God's hands while still employing his scientific knowledge.
He drew from the Hindu religion when he remembered the story of Markandeya and falling out of Vishnu's mouth into the universe. This inspired him to see how small and meaningless his suffering actually was.
He compared things that he saw to icons from Christianity. The orangutan on the island reminded him of the Virgin Mary floating toward him. In addition, when that same orangutan was killed he compared it to crucifixion of Jesus Christ. His Christian beliefs lead him to accept that even if he did not survive this ordeal he would be redeemed because of his faith.
He employs the theories of Islam when he sees lightening and compares it to a strike from Allah. He believes that he has to coexist with all creatures because they are all one entity according to the teachings of Islam.
Although he depends heavily on his religious beliefs, Pi is scientific about his needs for survival. He examines situations on how to survive in different types of weather, how to meet his basic need for food and water, and how to deal with a wild animal. He hypothesizes, experiments, and attempts to solve the various problems he encounters.