"And you, son of Man, take for you one branch and write on it 'for Yehuda and the Children of Israel his compatriots,' and take one branch and write on it 'for Yoseif, the branch of Efraim and the entire House of Israel, his compatriots.' And you should draw for you one near to the other unto one branch, and they shall be united in your hand.... So says G-d: 'Behold I shall take the Children of Israel from amongst the nations to which they went, and I shall gather them from around, and I shall bring them to their land. And they shall no longer be two nations and will no longer be split into two kingdoms... and they shall be one nation and I shall be their G-d. And my servant David will be king over them and [there will be] one shepherd for all of them, and they shall walk in my laws, and my statutes they shall keep and perform them." (Yechezkel 37:16-24)
Haftoras VaYigash contains these prophetic words of consolation by Yechezkel of the eventual gathering and unification of the Jewish people. The Haftorah echoes the dramatic reunification of Yoseif and his brothers in Egypt after years of envy, hatred, suspicion and separation. It would appear that this reunion served as an example -- Ma'aseh 'Avot Siman laBanim (the actions of the forefathers are a sign for the children) -- for their descendants.
There is a direct parallel between the dual events mentioned in the prophecy -- the gathering of the Jewish people in Eretz Yisrael mentioned in the prophecy ("and I shall gather them from around, and I shall bring them to their land") and their reunification as a cohesive unit ("and they shall be one nation and I shall be their G-d") -- and the tenth blessing of the Shemone 'Esrei. There we pray: "v'sa neis l'kabeitz galuyoseinu, v'kab'tzeinu yachad mei'arba kanfos ha'aretz..." -- "and raise a banner to gather our exiles, and gather us together from the four corners of the Earth." The blessing repeats the ingathering of the exiles twice in a seemingly redundant fashion. Rav Shimon Schwab (in Rav Schwab on Prayer, Artscroll/Mesorah) suggests that the first "gathering" refers to the physical return of K'lal Yisrael to its Holy Land; the second "gathering" refers to the reunification of the ideologically splintered Jewish people.
Yechezkel expresses the reunification of B'nei Yisrael as the reunification of Yehuda and Yoseif. On a simple plain, this references the split into two kingdoms headed by rulers from these two tribes. Perhaps we can suggest another meaning highlighting the reunion of two different types of Jews. Throughout the ages, there have always been two models of 'Avodas Hashem: the approach of exclusive devotion to Torah study and directly spiritual pursuits and the approach of combining Torah study with a greater involvement in the world, whether professionally or academically. Stellar models of both have existed throughout Jewish history. Rav Soloveitchik suggested that this duality was the root of the dispute between Yoseif and his brothers. Yoseif's approach to the Service of G-d would be to infuse the entire mundane world with sanctity by engaging it and elevating it. (See Sheim MiSh'muel where he explains that this concept is one symbolic idea behind the placement of the Chanuka Menora which represents the light of Torah outside the house demonstrating that the Torah must illuminate all aspects of the outside world.) Indeed, Yoseif's roles as trusted manager, dream interpreter, economist, viceroy, and orchestrator of history while remaining loyal to the traditions of his father's household serve as a prototype of this type of Jew. Yehuda and his brothers espoused a more insular approach focusing on Torah study without as much involvement in the world at large. Ultimately, the reunification of the brothers represented the validity of both approaches. K'lal Yisrael has twelve tribes. Some, such as Leivi and Yissachar, would exclusively dedicate their lives to Torah study serving as the central foundation for the accurate transmission and interpretation of Torah for all generations. Others would engage in professions, trades and agriculture and support those engaged exclusively in Torah study. Individuals from all tribes could become "honorary members" of Sheivet Leivi choosing a Torah-alone lifestyle sensing that as their calling. (See Rambam, end of Hilchot Sh'mitta V'Yoveil, also Shulchan 'Aruch O"C 157 and Bei'ur Halacha s.v. "ya'asok").
Although each of these two prototype-members of K'lal Yisrael performs a valuable, indispensable role, often, since they are so different from each other, their differences could lead to arguments or even fissure as happened, according to Rav Soloveitchik, in the case of the original Sh'vatim. The prophet foretells the state of redemption when all the factions of B'nei Yisrael unify recognizing that through their diverse but complementary roles they all partook in bringing the Glory of G-d to the world.
Of course, we need not wait for the final redemption to start the process. It is incumbent upon all members of the Jewish people to recognize legitimate although distinct approaches to 'Avodas Hashem all with the Torah and Taryag Mitzvot ("and they shall walk in my laws, and my statutes they shall keep and perform them") as their foundation and to embrace diversified unity based on the Torah within our ranks. (For a further expansion on diversified unity, see The Nazir, N'si'im, and Nuances on TorahWeb.org.)