If karma were true, we’d all be be screwed. While some of us might not suggest that we actually believe in Karma, there are many of us who do believe it. Because the idea that you’ll get what you deserve is an appealing way of looking at the world. People, regardless of their faith background, like to think that if they do something good, something good will happen in return.
But the problem with Karma is that it leaves us with some crappy possibilities.
If karma is true, everything evil that happens is because of something that we've screwed up.
If somebody believes in karma and doesn’t feel like things are going poorly for them, I’d suggest that they have an arrogant view of themselves. Karma suggests that everybody gets what they deserve. This means that if somebody is rewarded, they get the credit. And if somebody is punished, they get the blame.
This means if things are going well - if you got the job, the marriage, the house - then you are receiving the rewards for what you have done. But if things are going poorly - if you lost your job, your marriage is falling apart, or you have an incurable disease - then you are receiving exactly what you deserve.
In this world nothing happens to a person that he does not for some reason or other deserve. Usually, men of ordinary intellect cannot comprehend the actual reason or reasons. The definite invisible cause or causes of the visible effect is not necessarily confined to the present life, they may be traced to a proximate or remote past birth. - Buddhanet.net
This is completely contrary to doctrines like grace and mercy.
Grace knows what we deserve. And it gives us the opposite. And in the face of things going poorly, grace - instead of trying to answer why - simply promises to be with us in the midst of the pain.
What is grace? Grace is love that seeks you out when you have nothing to give in return. Grace is love coming at you that has nothing to do with you. Grace is being loved when you are unlovable. It is being loved when you are the opposite of lovable. - Paul Zahl
Grace is the enemy of karma.
Because while karma would suggest that we will end up damned, grace gives us eternal life. While Karma would suggest that it is all about our work, grace suggests that it is all about the work of Jesus.
What if the Apostle Paul believed in karma?
“None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.” - Romans 3:11-12
Paul would suggest that if karma is true, we are all going to hell. But that is what makes grace so scandalous. We don’t get what we deserve. We deserve death. We deserve punishment. And we get grace, peace, and mercy. We receive forgiveness. And it has nothing to do with what we’ve done.