From our earliest days, many people have believed in a power or powers greater than themselves. This belief is known as religion. In ancient times, it was a way to make sense of the mysteries of the natural world; evil spirits were thought to be responsible for bad weather and disease, for instance. Ancient peoples felt that they had a measure of control over their lives when they made offerings and prayed to friendly spirits, whom they believed could help them win battles or grow better crops. Even today, when people know the scientific explanations for such things as thunder or the eruption of volcanoes, many look to religion to explain some of the other hard-to-understand things that we experience as humans things like the purpose of life or the reasons for tragedies.
While most religions spring from the same basic human need to believe in a great power or powers, the ideas, practices, and traditions that religions involve can be very different. Long ago, groups of people separated by things like deserts, mountains, or great oceans developed special religious beliefs and forms of worship that fit their unique ways of life. Some, like the ancient Greeks, built their religions around the belief in several gods (a practice called polytheism), while others, like the Jews, believed in a single god (monotheism). Great temples, shrines, and churches were built to honor these gods, and believers showed their faith through ceremonies, sacred writings, prayers, and other forms of worship. As civilizations developed and ways of traveling long distances improved, explorers, traders, settlers, and missionaries spread different religions to other parts of the world. As religions spread, they were often changed into different forms that better fit the conditions and people of various lands. All the major religions of the world began in Asia before they gradually spread to other parts of the world Judaism, Christianity, and Islam in the Middle East; Buddhism, Hinduism, and Sikhism in India; Taoism and Confucianism in China; and Shinto in Japan.