The world of Beriya, the world of Creation, is a tremendous step down from the world of Atzilut. Beriya, or "creation", implies limited reality, or bringing into being a restricted existence. The dimension, the limitation, which is added by the descent of the light into the world of Beriya is the very concept of "being", as opposed to the "nothingness" of Atzilut.
In the world of Beriya the vessels begin to obscure the light
Atzilut is a world of non-being, because the structuring of the light by the vessels is not a hindrance or an obscuring of the light, as it is in the world of Beriya. Unlike Atzilut, however, in the world of Beriya the vessels begin to obscure the light and thereby create limited beings. This can be understood by way of an analogy: if one were to go out on a day so sunny and bright that he would not be able to see anything if he kept his eyes wide open, he would have to almost close his eyes in order to see. In such a scenario, squinting his eyes, he can only make out vague shapes. With sunglasses, however, he can see better -- he can see things clearly. This is like the world of Beriya in that the clear form and existence of things only becomes apparent when the light is sufficiently dimmed and obscured. Of course the analogy is imperfect since the objects which one sees with sunglasses were always separate, individual objects -- which is not entirely true in the world of Atzilut.
Between the way one understands something and his ability to explain it to someone else, there is a tremendous gap. In the world of Beriya, we are not even talking about actually explaining an idea to another person. We are still talking about planning in one's mind how one would explain it to another person before actually doing so. In the world of Atzilut, the structuring of the original flash of inspiration, the original idea, was only in one's own understanding; in addition, his grasp of the idea was proportionate to his own ability to comprehend. In the world of Beriya, however, there is an additional factor, namely the limitations of the recipients or interpreters of that which is meant to be conveyed. A teacher who wants to explain an idea to his student first has to measure the capability of his student to understand, and the teacher has to tone down and limit the idea accordingly. In fact, although for his own understanding it is not necessary for him to break the idea down into various simpler components, for his student he must do so. This is because the student is, as yet, unable to grasp a vast complexity of ideas all at once as the teacher does.
Beriya is considered to be outside of the realm of the Infinite Light
The word Beriya in Hebrew signifies "outside of." This implies a new level of separation, for Beriya is considered to be outside of the realm of the Infinite Light. That is to say that in Beriya the Infinite Light is concealed to such an extent that it is considered as separate from the Infinite Light, even though, as we pointed out before, there is no place devoid of the Infinite Light. An analogy is used in the Kabbala to explain the relationship between Beriya and Atzilut: the light of Atzilut is like the light of a candle in a room, and the light of Beriya is like the light of the candle as it is seen on the other side of a curtain which closes off the room.
In a subjective sense, the awareness of separation implies that one is conscious of one's existence as a distinct (albeit dependent) entity.
The next article in this series: Forming Time and Space.