Recently, I have been listening to an unbelievable series of Hashkafa tapes from Rav Shimon Kessin. There are some wonderful ideas that I wanted to share that pertain to Moshiach.
We all know that we are waiting for Moshiach, but what is this business of two Moshiachs? We have Moshiach ben Yosef and Moshiach ben Dovid, but why do we need two? Isn't one enough?
So we need to understand that it all goes back to the sin of Adam Harishon. If Adam Harishon would not have sinned, he would have been Moshiach himself. The way Rav Kessin explains it is that the job of Moshiach is to bring down a certain transcendent level of the soul, which is called the Yechida, and thereby attain a tremendous revelation of the Divine. This was what Adam would have accomplished had he kept his mitzvah. This would have brought about what we call a תיקון החסרון - a rectification of his lack. He would have entered straight into Olam Haba by doing this.
Another way of saying this would be that Adam was at a level of 0. By keeping the mitzvah, he would have gotten to the level of 1. By transgressing, however, he entered the level of -1. This means that he created the necessity for a new תיקון, which was the rectification of the damage he had caused.
So now we have two rectifications that are neccessary after Adam's sin - תיקון החסרון - rectifying the lack (or going from zero to one) as well as תיקון הקלקול - rectifying the damage done by the sin (or going from -1 to 0).
These are the two jobs of the two Moshiachs. Moshiach ben Yosef's job is fix the damage done by the sin, to bring the world back to its state before Adam Harishon's sin. Moshiach ben Dovid's job is to complete the rectification of the lack that existed previous to Adam Harishon's sin. Both of the Moshiachs do this by bringing down the level of Yechida - the transcendent level of the soul.
Both of the Moshiachs are not only specific people, but also represent the process by which the תיקון comes about. This is what is meant when we say that each generation has its Moshiach - each generation has a person who is outstanding in the process of the תיקון that is required, and helps to move the Jewish people in that direction. Thus we find that the students of the Gra revealed that the Gra was Moshiach ben Yosef of his generation. The Gra accomplished this task by being involved in the mysteries of the Torah to a great extent, as well as encouraging his students to begin a return to Israel, which they accomplished when they arrived here in Israel in 1808. They were extremely instrumental in establishing and sustaining the Yishuv of the areas around the old city of Jerusalem. We also find that the Ari Hakadosh was the Moshiach ben Yosef of his generation, thus we find him revealing secrets of the Torah that had never been revealed before.
Another point that I found was interesting was that we find that Moshiach ben Yosef can be from any tribe. In fact, Moshe Rabbeinu himself would have been Moshiach ben Yosef in his generation if the Jewish people had not sinned with the Golden Calf. Yet he was from the tribe of Levi. We also find that Shaul Hamelech would have been MBY of his generation had he not sinned by allowing Agag to live, and again he was not from Yosef, but rather from Binyamin. Moshiach ben Dovid, on the other hand, must come from the physical lineage of Dovid (and Yehuda).
Rav Kessin explains that Moshiach ben Yosef's role is the role of the leader of the Jewish people. This is something that can be fulfilled by anyone. The role of Moshiach ben Dovid, however, is that of a king, and a king must have royal blood.
The Damesek Eliezer gives a further explanation of this, and says that the concept of Moshiach ben Yosef represents the male aspect, as it corresponds to the Sefirah of Yesod. Moshiach ben Dovid, on the other hand, corresponds to Malchus, the female aspect. Thus, the male aspect always represents the infinite potential which is not contained, somewhat like water without something to hold it. Thus Moshiach ben Yosef can come from any tribe. Moshiach ben Dovid, however, is the female aspect, which is definition and constriction, and thus he must be from a specific tribe.
So now, when we talk about the Moshiach that we are waiting for, we need to realize that we are first waiting for Moshiach ben Yosef, whose job is to return us to the state of Adam Harishon before the sin. His job involves revealing the secrets of the Torah, as well as bringing the Jewish people back to Israel and rebuilding the physical Temple. As we said, his job is not reserved for himself exclusively, bat rather it is also an ongoing process, which is clearly taking place as we speak. It seems that the man himself will come and complete the process, thus returning us to a stage of complete revelation of Hashem's presence and a recognition of His guiding Hand throughout history. He raises us out of the קלקול created by Adam and returns us back to the stage before the sin. Then, Moshiach ben Dovid takes over, to complete the process of the תיקון החסרון - rectification of what we lack, or going from zero to one. This is represented by the fact that he brings the Shechina into the Temple that MBY has built.
It is important to note that Moshiach Ben Dovid's job is also a process that takes place throughout history. What this means is that when the times of Moshiach actually occur, we will actually be on a higher plane that Adam was before the sin. This is because before Adama sinned, he did not rectify any of the חסרון. Throughout history, the two processes of Moshiach ben Yosef and Moshiach ben Dovid have been occuring simultaneously, thus there has been a rectification of both the destruction he caused as well as a movement upward at the same time. This means that we will be on a higher level then Adam when Moshiach comes.
This explains a perpelexing question. If Adam Harishon could sin in the higher state, what is to say that we won't sin like Adam did at that time, and reintroduce the destruction? Isn't it possible that Moshiach will come and we will mess up again?
The answer is that, as we said, since Moshiach has taken so long to come, and we are nearing the year 6000, the amount of rectification that is left is very small. Most of it has been done. Thus, when we return to his state, the yetzer hara will be so small that it will be guaranteed that we will never return to the state we are in now, but rather the transformation will be complete and permanent.