Abraham is a figure in the Old Testament considered to be a precursor of the world's three great Western religious traditions: Judaism, Christianity, and Islam, called the Abrahamic religions. The Judaeo-Christian religions exclude Islam.
Abraham’s wife, Sarah, was unable to bear children, so he took a second wife; Hagar, an Arab maidservant. Hagar bore Abraham a son, Ishmael. Thirteen years thence, Sarah bore Abraham another son, Isaac. At Sarah’s insistence, Abraham banished Hagar and Ishmael, and it is from this point that split between Arab and Jew was traditionally derived.