This appeared on a mailing list and I have it by kind permission of the author. As Halloween approached, a pagan seeker was mourning the loss of her child, and wondering about evil and pain in the world. I think this is a really good response.
As to your question. One thing I want to say is that the Craft doesn't really give us a pat, dogmatic answer to most of these kind of questions. It offers us the means to consider them and we each end up coming to our own conclusions, so what I offer may be very different then the conclusion you or anyone else comes to. I can be long winded. I will try to be succinct but please bear with me.
Einstein once said, "the question isn't is there a god. The question is whether he had to make the universe the way he did?"
So, I was confronted with the idea of bad things. I don't believe in "evil" as an external objective force in the universe. The oldest meanings of good and evil mean simply things that we like and think will benefit us and things we don't like and think will harm us. So evil is "things that I, my group, or my culture don't like and think will hurt us" (i.e. bad things). Why do they happen? Why do the Gods let them happen? What does it mean that the Gods let them happen?
Now I go back to Einstein and the universe (and again, please bear with me). Time exists because of space. Before the big bang we have singularity. All things were one thing. No individuality, no I and you. No thoughts (which require space). What the Hindus would refer to as undifferentiated divinity. No space and so no time.
After the big bang, things become separate. Space comes into existence. Now there is an I and a you. Because one piece of matter cannot be both here and there, time exists. I must move from here to there to get from here to there. I can't do this immediately. Space creates time.
Moving from here to there creates friction. In fact simply being in the field of time (were there is space and no singularity) creates friction. Friction is actually the nature of the field of time. Things colliding with things, whether on the sub atomic level or on the macro cosmic level. And friction hurts. Whether it is a baby being born or a plant forcing its way out of the earth, friction hurts and suffering occurs.
Two other things that seem to be in the nature of the field of time. First; life lives on life. We, all of us, live off of the life of other things. We need to kill and consume life in order to exist in the field of time. This process is filled with pain and suffering.
Second; because of space, we now have choice. Because I am not in singularity, I can go here OR there. In fact anything that has will, must make choices. Space enforces this on us. Even choosing to do nothing is a matter of how we interact with space and other matter within space. All choices will bring suffering to something/one. If I move, something or someone suffers and or dies. Be it on the subatomic Level or the macro cosmic level, choice creates suffering. Everything is "bad" for someone/thing.
What has all this to do with evil? Well, for me it defines how the universe "is" and that gives me a starting point. Evil (bad experiences) exist because of how the universe works. Because of space and the friction and choice that are integral to it.
So, the next question that occurred to me was why create the universe this way? The first thing I noted was that the universe is the Gods. We all come from singularity and singularity is everything, undifferentiated. So the gods experience the universe, both through us and through everything else.
The next thing I noted was that the Gods clearly don't mind the suffering and bad experiences of the field of time, or at the least, they are willing to accept the existence of such things for the pay off of whatever it is that our universe offers.
And that made me think my next question which was; What is it that can happen in our universe that makes it worth experiencing the suffering and pain? It had to be something that couldn't be experienced in singularity or else why create the field of time? And it had to be something that only space (the defining characteristic of our universe) would allow for.
The Craft offers an answer to this question. It suggests it in the characteristics of our Gods and in the stories we have about them. The reasons our Goddess is in the role of rulership and what we look for within our religion itself.
In order to experience love we must have separateness. If there is no I and you then I cannot long for you. The feeling of desire in the hearts of man can only happen here in the field of time. And it can only happen with the existence of friction and choice. Our Goddess is a Goddess of love and desire. To have that ultimate experience the divine must enter the field of time. And it seems, that it is worth the pain and suffering inherent in the universe, for them, in order to have that experience.
So, back to the less esoteric meanderings. Why do people do bad (evil) things? Because they can. Because the world is set up so that bad thing can happen. Given the option, some folks will all ways opt for doing something that will hurt someone else. Either from selfishness (lack of emotional maturity), mental illness (sickness or compulsion), pain (lack of awareness of other) or just plain meanness (lack of spiritual maturity).
The universe is set up so it can happen and so it does. The real question is how we deal with this behavior. Do we become hateful ourselves or do we take comfort and love from those we care about. Do we seek our center and act to make our world the best place we can or do we retreat and hide and seek to opt out of the experience.
The Buddhists refer to it as "Joyful participation in the sorrows or the world". So when my mother died, I grieved and still do on occasion. I wished for so much more for her and us. Then I set it aside and jump back in, even while I still may feel the pain.
If you've ever seen the movie Harold and Maude (and if you haven't I strongly suggest it), there is a seen wherein Maude is trying to explain this to Harold (who wants to opt out). She says something to the effect that if you don't take part in the game, you won't have any stories to tell back in the locker room. It would be a shame to get done here and not have any stories to tell.
It seems to me that Einstein had it right. The question is; did the Gods have to make it this way in order to achieve what they set out to achieve". I think the answer is yes.
So, there you have it. My take on evil and suffering and why things are like they are and what makes it worth it all. Sorry for the length