G‑d taught Moses the procedure for kindling the lamps of the Candelabrum. He then began to describe how to fashion the special garments of the priests.
The Priest Within
וְאַתָּה הַקְרֵב אֵלֶיךָ אֶת אַהֲרֹן אָחִיךָ וְאֶת בָּנָיו אִתּוֹ . . . לְכַהֲנוֹ לִי וגו': (שמות כח:א)
[G‑d told Moses,] “You must draw your brother Aaron to you, together with his sons, to minister to Me [as priests].” Exodus 28:1

It would seem that we should all want to be priests, consecrated to G‑d and totally steeped in Divine consciousness. This is indeed a worthy ideal, but if it were put into practice, it would undermine the purpose of Creation. G‑d created us not to be angels but human beings who live in the mundane world. Only this way can we can elevate the world, refine it, and fill it with Divine consciousness.

On the other hand, in order to elevate the world, we need to preserve an image of the totally Divine way of living that we are striving to elevate it to. Hence, a select minority of the people had to live out this ideal in practice; they were the priests. Similarly, we must all consecrate a portion of our personality to the sole purpose of serving G‑d. By creating (“installing”) this “inner priest,” we can then relate to the world at large as we are meant to, guiding and leading it to its Divine fulfillment. This is how we fulfill G‑d’s promise to us when He gave us the Torah: “You will be unto Me a kingdom of priests and a holy nation.”1