Christianity is the world's biggest religion, based on the life and teachings of Jesus Christ in the first century AD. The monotheistic religion has more than two billion followers all over the world.
The Roman Catholic Church, the Eastern Orthodox churches and the Protestant churches are Christianity's largest branches, and there are also numerous sects throughout the world. The Christian holy book is the Bible, and believers worship in churches. Practices include prayer, Bible study, baptism, the Eucharist (Communion), church on Sundays and several holidays. Symbols include the cross, the dove and the fish.