Judaism, Christianity and Islam are monotheistic religions that originate from one root. Namely, "the father of all nations" Abraham was recognized by all three religions as the founder of monotheism, who knew one God. The descendants of Abraham's second son, Isaac, Jews are the founders of Judaism, while the descendants of Abraham's first son Ismail, Arabs are the founders of Islam, that is, Muhammad. Christians who acknowledge the principles adopted by Abraham, the early followers of Christ were also Jews, the heirs of Abraham. Christians and Muslims have contributed to spreading the idea of one God, the Abraham's God, Christians mostly by the 4th century, and Muslims from the 7th century.