The Book of Genesis (from the Latin Vulgate, in turn borrowed or transliterated from Greek γένεσις, meaning "origin"; Hebrew: בְּרֵאשִׁית, Bərēšīṯ, "In [the] beginning"), is the first book of the Hebrew Bible (the Tanakh) and the Christian Old Testament.
The basic narrative expresses the central theme: God creates the world and appoints man as his regent, but man proves disobedient and God destroys his world through the Flood but preserves a righteous man, Noah, and his family. The new post-Flood world is equally corrupt, but God does not destroy it, instead calling one man, Abraham, to be the seed of its salvation. At God's command Abraham descends from his home into the land of Canaan, given to him by God, where he dwells as a sojourner, as does his son Isaac and his grandson Jacob. Jacob's name is changed to Israel, and through the agency of his son Joseph, the children of Israel descend into Egypt, 70 people in all with their households, and God promises them a future of greatness. Genesis ends with Israel in Egypt, ready for the coming of Moses and the Exodus. The narrative is punctuated by a series of covenants with God, successively narrowing in scope from all mankind (the covenant with Noah) to a special relationship with one people alone (Abraham and his descendants through Isaac and Jacob).
Tradition credits Moses as the author of Genesis, but the book is in fact anonymous; current thinking places the first draft of Genesis either just before or during the Babylonian exile of the 6th century BCE, and the final edition in the late Exilic period or soon after. The author or authors appear to have structured it around ten "toledot" sections (the "these are the generations of..." phrases), but many modern commentators see it in terms of a "primeval history" (chapters 1–11) followed by the cycle of Patriarchal stories (chapters 12–50). For Jews and Christians alike, the theological importance of Genesis centers on the covenants linking God to his Chosen People and the people to the Promised Land. Christianity has interpreted Genesis as the prefiguration of certain cardinal Christian beliefs, primarily the need for salvation (the hope or assurance of all Christians) and the redemptive act of Christ on the Cross as the fulfillment of covenant promises as the Son of God.