Karma is NOT a Christian concept. It is defined thusly on google.com:
(in Hinduism and Buddhism) the sum of a person's actions in this and previous states of existence, viewed as deciding their fate in future existences.In American culture, we have the saying, which could be loosely related to Karma, "what goes around, comes around."
In essence, this speaks to a cosmic force that comes back to get you when you do something bad. You certainly won't find the word "karma" in the Bible and you will never find proper reference to God and Karma. (You might find a reference to a "god" and Karma, but not the Living God.)
There ARE consequences for your actions; this much is true. The Bible says that "the wages of sin is death." But the whole idea of karma is that the universe (which is attributed with some of the characters of God) must keep things in a balance of good/bad. This is a counterfeit of what God has ordained. And remember, ALL religions (other than Judaism and Christianity) are counterfeits created by the devil to deceive and confuse people from worshiping the True and Living God.
Then, we come to the idea of becoming angels when we die. We see this most often when someone passes away and someone (with good intentions) say something like "Heaven needed another angel." Dear friends, people DO NOT become angels when we die. Angels are created beings that are a whole different class than humans. Angels CANNOT be saved. The angels that sided with Satan will never be redeemed. Jesus died for people, not angels.
There is no indication in the Bible that we will have wings when we get to Heaven. In fact, the Bible talks about the role of angels in Heaven that is separate from the function of the redeemed. Frankly, WE ARE BETTER than angels!
Why does this make any difference? What is the big deal if people talk about Karma or about becoming angels?
The big deal is that when CHRISTIANS talk about these things, it confuses people. We are called to be light in the darkness. Truth comes from God; lies from from Satan. When we perpetuate lies, we are unwittingly doing the will of the great deceiver. We are called out of the world. We can't just pick and choose what we like from the Bible and what we like from the world. It's "all or nothing".
Please, followers of Jesus, KNOW THE DIFFERENCE between God's Word and what the world teaches. Please don't "mix and match" to suit your own needs. That's how cults (like Mormonism & Scientology) get started.
Read and STUDY your Bible! BE light in the Darkness! Live a life of TRUTH in a world of lies!