Reading Carl Jung's writings on acceptance of our dark aspects has been so deeply healing for me.  I don't know if others will feel the same, but it's a sort of key to tranquility.  You can also listen to Alan Watts describe Jung's views on "evil" on YouTube.  He really summarizes it well.

Here's a quote from one of Jung's psychotherapy patients.  The second quote is from the Gnostic text "The Gospel of Thomas".  And third, I will quote a section from Walt Whitman's "Song of Myself".

"Out of evil, much good has come to me. By keeping quiet, repressing nothing, remaining attentive, and by accepting reality - taking things as they are, and not as I wanted them to be - by doing all this, unusual knowledge has come to me, and unusual powers as well, such as I could never have imagined before.
I always thought that when we accepted things they overpowered us in some way or other. This turns out not to be true at all, and it is only by accepting them that one can assume and attitude towards them. So now I intend to play the game of life, being receptive to whatever comes to me, good and bad, sun and shadow forever alternating, and, in this way, also accepting my own nature with its positive and negative sides. Thus everything becomes more alive to me. What a fool I was! How I tried to force everything to go according to way I thought it ought to. "
-  an ex patient of C. G. Jung (Alchemical Studies, pg 47)

-----

"His disciples said: On what day will you be revealed to us, and on what day shall we see you? Jesus said: When you unclothe yourselves and are not ashamed, and take your garments and lay them beneath your feet like the little children (and) trample on them, then [you will see] the Son of the Living One, and you will not be afraid"
- Gospel of Thomas, Saying 37

-------

"In all people I see myself, none more and not one a barley-corn less, And the good or bad I say of myself I say of them. I know I am solid and sound, To me the converging objects of the universe perpetually flow, All are written to me, and I must get what the writing means."
- From "Song of Myself" by Walt Whitman



