Theodicy, simply defined, deals with problem of why there is evil in the world.
The Christian explanation is that Adam and Eve committed the "original sin" and so human beings are "fallen" by nature and sin is part of their being. Jesus, so the myth goes, redeemed this fallen nature by dying on the cross and rising again. Evil exists in the world because of human's sinfulness.
There are Christian theologians like Matthew Fox who have pioneered a Creation Spirituality which teaches that humans were born with the "original blessing" and not "original sin" and that evil results from human's disconnection from nature and the transcendent nature of God.
Buddhists teach that human life is suffering which is born out of humans attachments to things. Were they not so attached and desirous and greedy they would not suffer. If they followed a middle path of moderation in all things they could achieve a degree of serenity.
Parker Palmer a Quaker says that evil is the result of disconnection, disconnection from oneself, one's family, friends, neighbors, and community, and from the transcendent gifts and means of life beyond oneself.
I can see the value in all these explanations and resonate to some degree with them all. However, I would say that the problem of evil is due to a lack of awareness. Evil is possible because a person or group of person's are not aware of themselves, of each other, and the interdependent web of life. In my thinking there are at least two types of lack of awareness: ignorance when people just don't know any better, and stupidity when people know better and choose the wrong path anyway because of desire, defensiveness, greed, etc.
So often people say, if I only knew then what I know now I wouldn't have done it. Well, why didn't you know? Love is blind, desire is blind, greed is blind, shame is blind, fear is blind, depression is blind, peer pressure is blind, etc.
As Pogo said in the old cartoon strip years ago, "I have seen the enemy and it is us." Indeed, we are our own worse enemy.
Socrates said "know thyself" and he also said "An unexamined life is not worth living". How many people do you know who live examined lives? How many people do you know who know themselves in any depth? Do you live an examined life? Do you know yourself in any depth?
Unitarian Universallism is a covenantal religion which believes in the inherent worth and dignity of every person, and believes in justice, equity and compassion in human relations, and believes in the free and responsible search for truth and meaning, and believes in the right or conscience and the use of the democratic process in our communities and in society at large, and believes in the interdependent web of all existence.
Unitarian Univeralism is one religion which promotes the value of awareness in oneself and in our communities and recognizes that it is the lack of awareness which leads people astray.
Awareness is facilitated by reflection, discernment, and mutual meaning making with acknowledgement and acceptance of the heretical. It is the heretic who keeps us honest and challenges our taken for granted smugness and self congratulating arrogance.
I am suggesting that the problem of evil does not require some esoteric mythology or theology. Using Occam's razor it can be explained more simply as the result of human beings ignorance and stupidity. The only devil in the world is the idiocy which is in all of us.
For a further discussion of theodicy I invite you to join our UU A Way Of Live On Line discussion group. Just send me an email at firstname.lastname@example.org with your request and I will add you to the group.