Karma, as I understand it, is what some people believe is "payback". When you do certain things in life, whether good or bad, you will receive a reward that coincides with your acts. If you do good things, you will have good things done to you.
It seems to me that the idea of karma was created from a need to understand guilt. People live with the general understanding that there are rules that we live by. Whether they live in harmony with the Bible or some other code of conduct, they understand that there are good and bad actions. When we believe that there are approved methods for living, we feel guilty for not following those rules. By believing in karma, people find ways to justify their actions; if I do enough good things, they will outweigh the bad.
The reality, however, is that good or bad, we aren't judged on man's standard, but God's. If we don't live up to God's standard, then nothing else really matters. What we see as karma is the idea that when something happens that we deserve, we have a way to explain it. Isn't it possible, however, that when something happens that would be deserving, that it could just be part of life? I mean, we are hurt by people all of the time and yet when someone hurts us, we think that it's karma. Isn't that just part of life? When we speed in the car and then eventually get a ticket, it's not karma...it's just us getting caught.
I think we should stop trying to explain everything away and just accept the fact that life happens. When we get in trouble, it's an effect from us doing something wrong. So rather than expecting that it will affect what happens to us in the future, we should just accept blame and apologize to God.