Judaism
Christianity was originally a sect of Second Temple Judaism, but the two religions diverged in the first century. The differences between Christianity and Judaism originally centered on whether Jesus was the Jewish Messiah but eventually became irreconcilable. Major differences between the two faiths include the nature of the Messiah, of atonement and sin, the status of God's commandments to Israel, and perhaps most significantly of the nature of God himself. Due to these differences, Judaism traditionally regards Christianity as Shituf or worship of the God of Israel which is not monotheistic. Christianity has traditionally regarded Judaism as obsolete with the invention of Christianity and Jews as a people replaced by the Church, though a Christian belief in dual-covenant theology emerged as a phenomenon following Christian reflection on how their theology influenced the Nazi Holocaust.
Islamic schools and branches
In addition to these two main branches, many other opinions also formed regarding succession to Muhammad. The first centuries of Islam gave rise to three major sects: Sunnis, Shi'as and Kharijites. Each sect developed distinct jurisprudence schools ("madhhab") reflecting different methodologies of jurisprudence ("fiqh"). The major Sunni madhhabs are Hanafi, Maliki, Shafi'i, and Hanbali. The major Shi'a branches are Twelver (Imami), Ismaili (Sevener) and Zaidi (Fiver). Isma'ilism later split into Nizari Ismaili and Musta’li Ismaili, and then Mustaali was divided into Hafizi and Taiyabi Ismailis. It also gave rise to the Qarmatian movement and the Druze faith. Twelver Shiism developed Ja'fari jurisprudence whose branches are Akhbarism and Usulism, and other movements such as Alawites, Shaykism and Alevism. Similarly, Kharijites were initially divided into five major branches: Sufris, Azariqa, Najdat, Adjarites and Ibadis. Among these numerous branches, only Hanafi, Maliki, Shafi'i, Hanbali, Imamiyyah-Ja'fari-Usuli, Nizārī Ismā'īlī, Alevi, Zaydi, Ibadi, Zahiri, Alawite, Druze and Taiyabi communities have survived. In addition, new schools of thought and movements like Quranist Muslims, Ahmadi Muslims and African American Muslims later emerged independently.