We cannot truly understand that which is beyond time and space as long as we are bound to these dimensions. We are fortunate enough to be able to understand that there is that which is beyond us, even if we cannot understand it. Kabbalah is the study of the Divine, and as such, it can never be fully understood. Yet with all we cannot know, there are still whole libraries of systematic Torah study of Divinity that we can know, supernal knowledge that requires tremendous depth of perception and understanding to learn. Although the Creator is Simple Oneness, from our perspective our eyes see physical objects that are clearly distinct from one another. Within Divinity, there are also distinctions that differentiate between different spiritual parts. One such distinction is between the words Kadosh (holy) and Kodesh (holiness): Although Hashem encompasses all holiness, He can be perceived as both that which instills the world with holiness and, at the same time, the source of holiness itself. This is the deeper meaning of the blessings with which observant Jews bless Him constantly. These blessing are an expression of our desire that His Holiness not remain exclusively in Heaven, but that it should make the world a holy place as well.
Besides blessings, there are other ways of achieving holiness in this world. The Kohanim were especially chosen to serve holiness. As such, they were commanded to observe extra measures of holy rites and behavior. For example, they must stay away from the dead, be more stringent about not shaving, about whom they marry, and about what they eat. Even things that are permissible according to the letter of the law must be left out. The Torah then commands them: "Kedoshim Yeheyu" they must strive to be holy… "Vehayu Kodesh, and they will become holiness.
Adapted from Rabbi Vali's book on Vayikra. Questions and subscriptions can be mailed to: the Yeshiva
Chag Kasher Vesameach