Christianity is the world's largest religion with an estimated 2.4 billion followers. Founded in Jerusalem in 33 CE, it is based on the life and teachings of Jesus Christ, revered as the resurrected Messiah. It has dominated western culture for centuries and includes three primary branches: Roman Catholic, Eastern Orthodox and Protestant. Christians believe in a single, all-powerful God recognised in 'trinity' form: God the Father; Christ the Son; and the Holy Spirit. The Bible is Christianity’s sacred text, encompassing the Old (Hebrew scriptures) and New Testaments.