Noah appears in Genesis 5:29 as the son of Lamech and ninth in descent from Adam. In the story of the Deluge (Genesis 6:11–9:19), he is represented as the patriarch who, because of his blameless piety, was chosen by God to perpetuate the human race after his wicked contemporaries had perished in the Flood. A righteous man, Noah “found favour in the eyes of the Lord” (Genesis 6:8). Thus, when God beheld the corruption of the earth and determined to destroy it, he gave Noah divine warning of the impending disaster and made a covenant with him, promising to save him and his family. Noah was instructed to build an ark, and in accordance with God's instructions he took into the ark male and female specimens of all the world's species of animals, from which the stocks might be replenished. Consequently, according to this narrative, the entire surviving human race descended from Noah's three sons. Such a genealogy sets a universal frame within which the subsequent role of Abraham, as the father of Israel's faith, could assume its proper dimensions.

The story of the Flood has close affinities with Babylonian (Babylonia) traditions of apocalyptic floods in which Utnapishtim plays the part corresponding to that of Noah. These mythologies are the source of such features of the biblical Flood story as the building and provisioning of the ark, its flotation, and the subsidence of the waters, as well as the part played by the human protagonist. Tablet XI of the Gilgamesh epic introduces Utnapishtim, who, like Noah, survived cosmic destruction by heeding divine instruction to build an ark.

The religious meaning of the Flood is conveyed after Noah's heroic survival. He then built an altar on which he offered burnt sacrifices to God, who then bound himself to a pact never again to curse the earth on man's account. God then set a rainbow in the sky as a visible guarantee of his promise in this covenant. God also renewed his commands given at creation but with two changes: man could now kill animals and eat meat, and the murder of a man would be punished by men.

Despite the tangible similarities of the Mesopotamian and biblical myths of the flood, the biblical story has a unique Hebraic perspective. In the Babylonian story the destruction of the flood was the result of a disagreement among the gods; in Genesis it resulted from the moral corruption of human history. The primitive polytheism of the Mesopotamian versions is transformed in the biblical story into an affirmation of the omnipotence and benevolence of the one righteous God. Again, following their survival, Utnapishtim and his wife are admitted to the circle of the immortal gods; but Noah and his family are commanded to undertake the renewal of history.

The narrative concerning Noah in Genesis 9:20–27 belongs to a different cycle, which seems to be unrelated to the Flood story. In the latter, Noah's sons are married and their wives accompany them in the ark; but in this narrative they would seem to be unmarried, nor does the shameless drunkenness of Noah accord well with the character of the pious hero of the Flood story. Three different themes may be traced in Genesis 9:20–27: first, the passage attributes the beginnings of agriculture, and in particular the cultivation of the vine (viticulture), to Noah; second, it attempts to provide, in the persons of Noah's three sons, Shem, Ham, and Japheth, ancestors for three of the races of mankind and to account in some degree for their historic relations; and third, by its censure of Canaan, it offers a veiled justification for the later Israelite conquest and subjugation of the Canaanites (Syrian and Palestinian religion). Noah's drunkenness and the disrespect it provokes in his son Ham result in Noah's laying of a curse on Ham's son Canaan. This incident may symbolize the ethnic and social division of Palestine: the Israelites (from the line of Shem) will separate from the pre-Israelite population of Canaan (which is depicted as licentious), who will live in subjection to the Hebrews.

The symbolic figure of Noah was known in ancient Israel, before the compilation of the Pentateuch. Ezekiel (14:14, 20) speaks of him as a prototype of the righteous man who, alone among the Israelites, would be spared God's vengeance. In the New Testament, Noah is mentioned in the genealogy of the Gospel According to Luke (3:36) that delineates Jesus' (Jesus Christ) descent from Adam. Jesus also uses the story of the Flood that came on a worldly generation of men “in the days of Noah” as an example of Baptism, and Noah is depicted as a preacher of repentance to the men of his time, itself a predominant theme in Jewish apocryphal and rabbinical writings.