Genesis, the first book of the Bible, opens with the Hebrew word bereshit, which means "in the beginning." The title "Genesis" was given to the Septuagint (Greek) translation of the book because of its concern with the origin of the world (Genesis 1:1; 2:4), of the human race, and, in particular, of the Hebrew people.

Eleven structural units (toledoth), of unequal length and importance, present the unity and purpose of the book in terms of God’s universal sovereignty, his dealings with men, and his choice and formation of a special people to be the instrument of his plan of salvation.

The tracing of the direct descendance from Adam to Jacob constitutes the major part of the book, while the genealogical tables of lateral branches are not so developed nor of such interest as those that pertain to the story of the Israelite people. In fact, these lateral branches gradually disappear from the narrative. And with the introduction of Abraham and his covenant with God, the history of humanity as such becomes contracted to the story of the descendants of Abraham through Isaac and Jacob - the chosen people.

Despite its unity of plan and purpose, the book is a complex work, not to be attributed to a single original author. Several sources, or literary traditions, that the final redactor used in his composition are discernable. These are the Yahwist (J), Elohist (E) and Priestly (P) sources, which in turn reflect older oral traditions (see Introduction to the Pentateuch).

In Genesis, the Yahwist source is the most important by reason of its teaching, its antiquity, and the continuity it gives the book. It constitutes a sacred history, continually drawing attention to the working out of God’s design through his interventions in the affairs of men. The Elohist source, less well preserved, is found in fragmentary form only, depicting God’s manifestations through visions and dreams rather than theophanies. Angels are God’s intermediaries with men. Moreover, there is a solicitude for the divine transcendence and greater sensitivity toward the moral order. The Priestly source contains those elements-chronological data, lists, genealogies-that construct the framework of Genesis and bind its contents together. To the J and E sources it adds such legal institutions as the sabbath rest, circumcision, and the alliances between God and Noah and God and Abraham.

The interpreter of Genesis will recognize at once the distinct object that sets Gen 1-11 apart: the recounting of the origin of the world and of man (primeval history). To make the truths contained in these chapters intelligible to the Israelite people destined to preserve them, they needed to be expressed through elements prevailing among that people at that time. For this reason, the truths themselves must therefore be clearly distinguished from their literary garb.

With the story of the patriarchs Abraham, Isaac and Jacob (Genesis 11:27-50:26), the character of the narrative changes. While we do not view the account of the patriarchs as history in the strict sense, nevertheless certain of the matters recounted from the time of Abraham onward can be placed in the actual historical and social framework of the Near East in the early part of the second millennium B.C. (2000-1500), and documented by non-biblical sources.

Genesis contains many religious teachings of basic importance: the preexistence and transcendence of God, his wisdom and goodness, his power through which all things are made and on which they all depend; the special creation of man in God’s image and likeness, and of woman from the substance of man; the institution of marriage as the union of one man with one woman; man’s original state of innocence; man’s sin of pride and disobedience; its consequences for the protoparents and their posterity. Despite the severity of their punishment, hope of reconciliation is offered by God through the first as well as the subsequent promises of salvation and blessing. Abraham is blessed for his faith and obedience, and he is to be a blessing for all nations through his offspring, Isaac, Jacob, and Jacob’s sons (Genesis 12:3; 18:18; 22:18), of whom the Messiah, mankind’s greatest blessing, will eventually be born (Gal 3:8).

Frequent references to Genesis are found in the New Testament. Christ becomes the antithesis of Adam: sin and death come to mankind through Adam, justification and life through Jesus Christ (Romans 5:12, 17-19). Noah’s ark becomes the symbol of the Church, by which men are saved from destruction through the waters of baptism (1 Peter 3:20-22); Abraham’s faith is the model for all believers; the sacrifice of his son Isaac typifies the sacrifice of Christ, Son of the Father. The Liturgy, too, relates the persons of Abel, Abraham and Melchizedek to Christ in his act of sacrifice.

The Book of Genesis is divided as follows:

I. The Primeval History (Genesis 1:1-11, 26)
  II. The Patriarch Abraham (Genesis 11:27-25, 18)
  III.The Patriarchs Isaac and Jacob (Genesis 25:19-36, 43)
  IV. Joseph and His Brothers (Genesis 37:1-50:26)