Olam HaBa (עולם הבא) — the World to Come
Core definition
Olam HaBa, "the World to Come," is the general name for the future world of reward and revelation — the "truth's world, a clear world," set against Olam HaZeh, "the falsehood's world" [15881/maamar_024 :: §324–378]. The corpus's systematic exposition divides it into "two general levels": "The first is the Olam HaBa that comes after Olam HaZeh — in which there are many levels without measure"; "the second level is the Olam HaBa of Olam HaTechiyah" [15881/maamar_024 :: §158–414]. The first is Gan Eden — souls without bodies delighting in the Shechinah's radiance; the second is the resurrection's world — souls clothed in bodies, in a revelation "such a wondrous revelation has never yet been" [15881/maamar_024 :: Summary (p. ריא)].
How the Rebbeim develop it
The first level: Olam HaBa after Olam HaZeh. "Gan Eden is the souls' reward on their Torah and mitzvos avodah — reward per avodah": "each and every one — per his matters' manner in Olam HaZeh, so he is for Olam HaBa"; "who learns in a yeshivah in Olam HaZeh learns in a yeshivah in Olam HaBa" — "each tzaddik his palace" [15881/maamar_024 :: §161–298]. In the soul's ascent from the body — after chibut hakever and kaf hakela purify the soul of the idle words' letters clinging from the thought and speech garments — "his soul, spirit, neshamah purified — he comes to his reward in Gan Eden's revelation, each per his avodah — particularly the tzaddikim ascending ascent after ascent ('they shall go from strength to strength'; 'from yeshivah to yeshivah')" [15881/maamar_024 :: Summary (p. ריב)]. The Talmudic formula is quoted: "not as Olam HaZeh is Olam HaBa — in Olam HaBa no eating, no drinking, no jealousy — but tzaddikim sit with their crowns on their heads and delight in the Shechinah's radiance" (Berachos 17a) — "souls without bodies" [15881/maamar_024 :: Summary (p. ריג)].
The ascent needs immersion. "That is: as the ascent from Olam HaZeh to Olam HaBa needs immersion. Because Olam HaZeh and Olam HaBa are two opposites": Olam HaZeh is "the falsehood's world" — "the yesh's whole matter is falsehood: all its existence only its Sustainer, to itself nothing — what is seen is the opposite: as if all its existence from itself" — while "Olam HaBa is the truth's world, a clear world." "Therefore in the ascent from Olam HaZeh to Olam HaBa they need immersion" — to forget this world's appearance; and so from lower to upper Gan Eden: "immersion in nahar dinur to forget the lower's delight, then receiving the upper's" [15881/maamar_024 :: §324–440].
The second level: Olam HaBa of Olam HaTechiyah. Here "souls clothed in bodies as in Olam HaZeh, only delighting in the Shechinah's radiance" [15881/maamar_024 :: Summary (p. ריג)]. "Not as the Yerushalayim of Olam HaZeh is the Yerushalayim of Olam HaBa — the Yerushalayim of Olam HaZeh: all who want to go up, go up; of Olam HaBa: none go up but those prepared for it" [15881/maamar_024 :: §445]. Even the highest souls — "the fathers, the tribes, Moshe and Aharon — 3000+ years" in Gan Eden, "ascending without measure" — "must clothe in their bodies for the future revelation," for this revelation, "never yet been," can only be received through the body [15881/maamar_024 :: Summary (p. ריד)].
The great revelation. "And the Havayah's honor shall be revealed, and all flesh shall see together, for the Havayah's mouth spoke" (Yeshayahu 40:5) — "the great and mighty revelation which shall be in the Olam HaBa of Olam HaTechiyah": "All these revelations are not in comparison and example at all beside that light and revelation which shall be in the future" — neither the revelations to Yackov and the fathers, to Moshe, to the tzaddikim, nor the general ones: the Exodus ("the King of kings revealed"), the Red Sea ("this is my Keil"), the Torah-giving ("and Havayah descended on the mountain" — "the essence's revelation"), the Beis HaMikdash ("as he comes to be seen, so he comes to see") [15881/maamar_024 :: §16–138].
Key distinctions
Olam HaBa (after Olam HaZeh) vs. Olam HaBa of Olam HaTechiyah. The first: souls without bodies, reward per avodah, many levels without measure; the second: souls in bodies, "delighting in the Shechinah's radiance," a revelation without precedent [15881/maamar_024 :: §158–414, Summary (p. ריג)].
Gan Eden vs. Olam HaBa. Gan Eden (lower and upper, "only Gan Eden lower and upper mentioned in the books") is the first level's content — "all called Olam HaBa" — but "all this is Olam HaBa's first level" [15881/maamar_024 :: §161, §411].
Olam HaZeh vs. Olam HaBa. The falsehood's world vs. the truth's, clear world — hence the need for immersion in the ascent between them [15881/maamar_024 :: §324–378].
Related concepts
Olam HaTechiyah (the resurrection's world, the second level); Gan Eden (the first level's domain); Techiyas HaMeisim (resurrection); The Shechinah's radiance (the delight of both levels); Moshiach; Chibut hakever and kaf hakela (the purifications before the ascent).