Many Worlds, One God: Judaism on Manifold Creation
I have just come to the shocking realization that my book, the Encyclopedia of Jewish Myth, Magic, and Mysticism, which otherwise provides a comprehensive summary of Jewish esoteric, aboriginal, mystical, and folkloric subjects, lacks an entry on one interesting topic - the tradition that ours is not God's first or only world! Oh, I mention it briefly in the context of other entries, but I did not dedicate an entry to that one matter, and that is an oversight. So here's what I know -
The teaching that God created multiple worlds before forming this world first appears in Bereshit Rabbah ("The expansion on Genesis"):
...And there was evening [the Hebrew can be read to suggest 'evening' was a reality before now]: hence we know a time order existed before this. R. Abbahu said: This proves the Blessed Holy One went on creating worlds and destroying them until He created this one....This is Abbahu's reason: And God saw everything that He made and behold, it was very good [comparatively] This pleases me, but those [worlds] did not please me. (3:7. Also see 9:2, where the same verse is used as a slightly different way - other sources also use Gen. 2:4: Now these are the generations of the heaven and earth when they [rather than "it"] were created, and Isa. 65:17).
How many worlds? Its unclear, but they added up to a thousand generations of souls, according to one reading, based on Ps. 105:8; 974 according to another. How that latter number? Noah was the 26th Generation of [this] creation, and since the Sages teach that Solomon was referring to Noah when he wrote, Only one man in a thousand have I found... (Eccl. 7:28), they deduct 26 from 1000 and get....974 (Gen. R. 28:4). 974 becomes the working number for prior creations in many subsequent retellings of this legend (Talmud Hag. 13b, Midrash Tehillim 90:13; Shabbat 88b):
R. Joshua b. Levi also said: "When Moses ascended on high, the ministering angels spoke before the Holy One, blessed be He: 'Sovereign of the Universe! What business has one born of woman amongst us?' 'He has come to receive the Torah,' answered He to them. Said they to Him, 'That secret treasure, which has been hidden by Thee for nine hundred and seventy-four generations before the world was created.'" (Shabbat 88b)
Hagigah 13b also gives us the piquant tradition that God did not jettison those earlier generations of souls, but continues to recycle them into the the unfolding generations of this world.
This idea that ours was not the first or only universe continues to be reiterated in various ways throughout the tradition (PdRE 3; Zohar I:24a-b; Or ha-Hayyim 1:12). In Hasidic tradition, the existence of prior worlds is revealed by the fact that the account of this creation begins with bet, the second letter of the Hebrew alef-bet (Gen. 1:1).
This tradition of diachronic universes exists separate from the notion of synchronic multiple worlds, which also exists in Jewish tradition in the (well-known) "Four Worlds" and "Seven Heavens" models, as well as the (not so well-known) "Seven Dimensions of Earth" model (Lev. R. 29:11; Seder Gan Eden; LOTJ p. 15).
Zal G'mor: To learn more, consult the Encyclopedia of Jewish Myth, Magic, and Mysticism: http://www.amazon.com/Encyclopedia-Jewish-Myth-Magic-Mysticism/dp/0738709050
 God is utterly committed to following proper outline format. Schwartz, Tree of Souls, p. 71.