Tzadik

1. Anyone who learns Chassidus, knows what a Tzadik is; but the Rebbe goes beyond even this, since the word Tzadik is a limitation.

Among other things, a Tzadik is someone who has no Yetzer Hora (drive for physical desires). This automatically makes him different than the average man.

And since he has no Yetzer Hora, he cannot sin. Which is why after a Tzadik is buried, his body does not deteriorate, (as has been documented numerous times), since sin causes the body to deteriorate.
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Since the Tzadik has no Yetzer Hora, he sees truth clearly, and is not misled by his own selfish desires.

Also, since the Tzadik is one, with Torah, he is able to perform miracles. Since Hashem put Himself into the Torah, and the Tzadik is able to connect with the inner aspects of the Torah, being its infinite part, he therefore can transcend nature.

2. But there are different levels of Tzadikim; the greater the Tzadik, the deeper levels of Torah he can connect with, and the more he can transcend the boundaries of nature.
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It is written, that a Tzadik cannot elevate Shlosha Kelipahs Hatamas, (the three lowest levels of impurity). Because, a Tzaddik is only involved in the world of Kedusha (holiness), and has no connection to evil.

But the Rebbe is not limited to the holy level of Tzadik- he made tens of thousands of Balle Teshuvah. And each Balle Teshuvah transformed their former Aveiras (transgressions), including Shlosha Kelipahs Hatamas, into Kedusha!
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A Tzaddik only brings holiness (which is a creation of Hashem) into the world; whereas Moshiach brings Hashem- an aspect of Etzem (Who is beyond all limitations) into the world.

On every continent of the world, the Rebbe has transformed darkness into light. Only something higher than darkness, can transform it into light- the power of Etzem!
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The world is made of up of three categories:
1. The body- Physical (limited)
2. The Soul- spiritual (infinite levels of Kedusha, holiness)
2a. Evil, (which is subcategory of the physical, can have a spiritual aspect to it), but it has only a temporary existence)
3. And the Etzem (essence) of Hashem - the complete unity of body and soul.

The spiritual, infinite level, is also just a creation, and is just as limited as the physical level; because it can only be infinite, and not finite; making it limited, to only being infinite.

Whereas Hashem, Etzem, transcends all boundaries, and therefore can be both finite and infinite, simultaneously; and can transform the lowest evil into holiness.

As was seen in the Beis HaMikdosh: The Aron Kodesh, had a measurement, but simultaneously had no measurement. Because in the Holy of Holys, the Etzem of Hashem was revealed. And although the Menorah in the Beis HaMikdosh had seven branches, the Chanukah Menorah has eighth.

Because, the Beis HaMikdosh only affected the realm of good, whereas Chanukah transformed the evil itself - eight shows on the level which is above the limitation of nature.
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This revelation of the aspect of Etzem in Moshiach, will eventually be revealed into the entire word- Geula!