Karmody.

One of my favourite sayings when something undesirable occurs, is that 'everything happens for a reason'. Another well said phrase is when a person does something bad, and people seem to always say that they'll 'get what's coming to them one day'.
Is this just a way of making ourselves feel better after a bad day? Or is it actually true? Do nasty people always get what they deserve?
Obviously, karma isn't something that can be proven (or disproven), but how does it work exactly? Obviously if you kill someone you'll go to jail, but what about the insignificant little things of every day life?
The belief of karma consists of the idea that God acts as a dispenser of the 'fruits of karma'. Whether people do good or bad, the idea is that we shape out our own path in life. There also seems to be a diluted equivalent to karma in the teachings of Christianity.
If there was such a thing as karma, surely we'd all do things that would consequently then happen to us, and we'd all be going around in a giant circle, wouldn't we?
However, if you are not religious, what stops you from doing bad things? Surely if you believe in karma, isn't this just a selfish way of deciding to not harm others? The fear being that you don't want to be harmed in return?
I guess there's a bit of karma in all of our lives though, on some level. If you help others, and don't harm anyone, you'll probably find that people treat you well, and maybe your good character can help you at work. But that's as far as a I can see in terms of karma.
Coming from an atheist's point of view, there is simply no way to comprehend how karma can exist. It does however, seem a nice thing to believe sometimes. If you do something that's deemed as bad, you obviously deserve the same to happen to you. It's a nice idea amongst many nice ideas religions have. But, sadly, that's not always how the fruits of karma crumble.