One of the major difficulties in philosophical and theological inquiry is how evil appeared in the world. If the Source of Life is all powerful, all loving, all knowing and all good, there is no possibility for evil to occur. One of the major kabbalists, Isaac Luria, the Ari, proposed an interesting idea in which he says that the Source of Life somehow contained and contracted a part of itself from which everything was excluded, including the power of love and goodness that was predominant in everything but this contraction.
The word for contraction is tzimtzim, and this doctrine of tzimtzum has been a predominant theme in mystical Judaism. Today, however, a different approach is becoming more prevalent that says good and evil are relative ideas and are dependant upon perspective and acculturation. This remains yet another difficult paradox for our exploration.