A Christian (/ˈkrɪstʃən, -tiən/ (listen)) is a person who believes in Christianity, an Abrahamic monotheistic religion. Christianity is mostly about the life and teachings of Jesus Christ, in the Bible's New Testament[1] and interpreted or prophesied in the Hebrew Bible/Old Testament.[2] Christianity is the world's largest religion, with 2.1 billion followers around the world.[1]