1. Founders are different: Judaism: Abraham, Christianity: Jesus Christ, Islam: Mohammed
2. How many followers: Christianity 2,200 million (2.2 billion) Islam: 1.5 billion Judaism: 14 million
3. Different groups: Christianity: Three main groups: Orthodox, Protestant and Roman Catholic, Islam: Two main groups: Sunni and Shia (The division occured due to a dispute as to the legitimate successor of the prophet Mohammed). There is also a mystical/ascetic movement in Islam known as Sufi, Judaism: Several divisions, including Hasidic, Conservative and Reform Judaism. Ethnic groupings include Ashkenazi (The majority) and Sephardi Jews.
