Judaism is the oldest of the Abrahamic religions. The term “Abrahamic” describes three faiths: Judaism, Christianity, and Islam. All trace the origins of their traditions to Abraham, described in the Hebrew Bible used by both Christians and Jews. Accounts vary in the Qur'an, the holy book of Islam. There is some dispute about whether Abraham is a historical figure who lived in the nineteenth century B.C.E. This section will also explore the four main Judaic variations: Orthodox, Hasidic, Conservative, and Reform. Each has its own set of observations, many of which date back to ancient times.