The purpose of Creation is for this world, a place of darkness and of forces of evil, to become a dwelling place for God, i.e., for God’s light to shine and be revealed in the world. In the messianic era, and after the resurrection of the dead, Creation will be brought to its ultimate purpose and perfection. The physical body, and the physical world, will be refined, and we will be able to receive the revelation of the divine light. The way to bring about the purification of the world is through the mitzvot that we fulfill during the exile.

The purpose of Creation is for God’s light to illuminate the darkness of this world:

The saying of the Sages is well known (Tanĥuma, Naso 24): The purpose of the creation of this world is due to the desire of the Holy One, blessed be He, to have a dwelling place in the lower world…so that God’s infinite light will shine in place of darkness and of the “other side” [i.e., the forces of evil and unholiness], throughout this world.

During the messianic era there will be a perfect revelation of light:

It is known that the messianic era, and especially when the dead are revived, constitutes the purpose and completion of the creation of this world, and the reason it was originally created…. The physical aspect of the human body and of the world will then become refined and will be able to receive the revealed light of God that will shine upon the Jewish people through the Torah which is called “strength,” [because it gives us the ability to receive this light]. Due to the abundance of light shining upon the Jewish people, the darkness of the nations will be illuminated as well, as it is written, “Nations will walk by your light” (Isaiah 60:3).

The future revelation of God’s light depends on our actions in the present:

This final perfection that will occur in the messianic era and at the resurrection of the dead, i.e., the revelation of God’s infinite light in this physical world, depends on our actions and our service of God throughout the duration of the exile. (Rabbi Shneur Zalman of Liadi, Tanya, Likutei Amarim 36–37)