Many religions - most notably Hinduism, Buddhism, and Sikhism - espouse a belief in Karma.
Karma, in Sanskrit, means "works" or "actions". In these religions, it's the notion that your actions will influence your future - which is common sense - but it's applied in a devious way when combined with the doctrine of reincarnation in order to form a truly monstrous and evil teaching.
If you live for any amount of time on this planet, you are confronted with the situation that is presented here by King Solomon:
Ecclesiastes 8:14
14 There is a vanity which is done upon the earth; that there be just men, unto whom it happeneth according to the work of the wicked; again, there be wicked men, to whom it happeneth according to the work of the righteous: I said that this also is vanity.
The origins of the beliefs in both Karma and reincarnation - the two are inextricably linked in these religions - are attempts to make sense of this dilemma, and suffering in general, without divine revelation.
The reasoning behind belief in Karma is easy to follow:
This line of reasoning leads to scriptures which say the following:
Brihadaranyaka Upanishad Book 7 Section 1
When body grows weak through age or disease, the Self separates itself from the limbs, as a mango, a fig, a banyan fruit separates itself from the stalk; man hastens back to birth, goes, as before, from birth to birth.
As a caterpillar, having reached the end of a blade of grass, takes hold of another blade, then draws its body from the first, so the Self having reached the end of his body, takes hold of another body, then draws itself from the first.
This Self is Spirit. He is knowledge, mind, life, sight, hearing, earth, water, wind, air, light, darkness, desire, absence of desire, anger, placability, right, wrong; He is everything; He is this and that. Whatever his conduct and character in one life, he has it in his next; if good in one, he is good in another; if a sinner in one, he is a sinner in another; his good karma makes him good, his sinful karma makes him sinful.
Hence they say that soul is full of desire. He wills according to his desire; he acts according to his will; he reaps what he sows. Here is my authority: "Self goes where man's mind goes. Whatever his actions in this world, he enjoys their reward in the next; that over, he returns for action's sake. I speak of a man with desire; but what is he who has no desire? He has no desire, because he has attained his desire; desire of Self is no desire. He does not die like others; he is of Spirit, he becomes Spirit."
Prashna Upanishad Section 6
Satyakama Shaibya asked: "Lord! Where does the man go after his life, if he meditates on Om all his life?" The Sage said: "Om is the conditioned and the unconditioned Spirit. The wise man with its help alone attains the one or the other.
If he meditates on the syllable A alone he is soon born again on this earth. If he has chanted the Rig Veda, he is born among men, a great, austere, self-controlled, God-fearing man.
Notice that both of the above not only teach reincarnation, but also predestination. "His good karma makes him good, his sinful karma makes him sinful", and if you chanted the Rig Veda, you will be a "great, austere, self-controlled, God-fearing man".
Therefore, because everyone is playing out the fruit of what they have done in a past life, the child born with a horrendous birth defect is not truly to be pitied. The person born in squalor, or to poor parents, or has some incurable illness, is likewise being punished for something that they did in a past life. It's only those born to a high Caste, those in power, or those who otherwise prosper, that are being rewarded for their virtue in a previous life.
Therefore, no matter your lot in life, they assure you that you are being punished/rewarded for past lifetimes lived that you (conveniently) have absolutely no recollection of ever having experienced.
Observe that:
This doctrine is the root and heart of the Caste System in India. Even though the Caste System is officially illegal in India today, it still affects the lives of millions of Indians, because it's enforced culturally, just as it has been for many hundreds of years - a rigid stratification of society, based on belief in reincarnation, and justified by the false doctrine of Karma.
First, it's important to address passages in the Bible which would appear, on their surface, to agree with the doctrine of Karma. For instance:
Galatians 6:7
7 Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap.
There are many verses which teach something similar to the above (Hosea 8:7, Proverbs 11:18, 22:8: 2 Corinthians 9:6). However, it would be a grave error to conflate the message of this verse with the doctrine of Karma.
The Word of God teaches "Whatsoever a man soweth, that shall he also reap". The doctrine of Karma teaches "Whatsoever a man soweth, that shall he also reap, but and if he doesn't, his sin will be brought to bear on him in a future life". As mentioned in the introduction, it's when reincarnation is involved that this doctrine becomes so unimaginably cruel and evil.
Although the principal of sowing and reaping is Biblical, it is not an explanation for all suffering that a person will undergo in their lives. The following passage is exemplary of this fact:
John 9:1-3
1 And as Jesus passed by, he saw a man which was blind from his birth.
2 And his disciples asked him, saying, Master, who did sin, this man, or his parents, that he was born blind?
3 Jesus answered, Neither hath this man sinned, nor his parents: but that the works of God should be made manifest in him.
Above, the misconception that the disciples had was that since the blind man was suffering, either he, or his parents, did something bad to deserve it. And, in response, the Lord directly refutes that misconception.
Not all suffering is retribution for sin. Some, to be sure, is (Proverbs 13:15), especially if you are a Christian (Hebrews 12:6). However, the idea that children born with birth defects, or otherwise difficult and painful conditions, are somehow to blame for their misery, is the height of demonic cruelty, slander, and injustice.
The book of Job is perhaps the best place to examine Karma in light of the Bible, because its main theme is an examination of a righteous man suffering for something that he did nothing in particular to deserve (Job 2:3).
In it, Job's friends, as evidenced by dozens of their statements, believed that Karma would come to bear with certainty on all evildoers. Therefore, they reasoned that the only explanation for Job's suffering must have been his sin:
Job 4:1, 7-8
1 Then Eliphaz the Temanite answered and said,
...
7 Remember, I pray thee, who ever perished, being innocent? or where were the righteous cut off?
8 Even as I have seen, they that plow iniquity, and sow wickedness, reap the same.
Job 8:1-6
1 Then answered Bildad the Shuhite, and said,
2 How long wilt thou speak these things? and how long shall the words of thy mouth be like a strong wind?
3 Doth God pervert judgment? or doth the Almighty pervert justice?
4 If thy children have sinned against him, and he have cast them away for their transgression;
5 If thou wouldest seek unto God betimes, and make thy supplication to the Almighty;
6 If thou wert pure and upright; surely now he would awake for thee, and make the habitation of thy righteousness prosperous.
Notice their tone. They insinuate that if Job was innocent, God would be unjust to let him suffer this way, and surely if he were righteous, God would have helped him by now, otherwise God's righteousness is called into question. This is the same faulty reasoning that underpins a belief in Karma.
Later in the book, Job states that had the tables been turned, he wouldn't have reasoned the way that his friends did, and would instead comfort them despite their misery:
Job 16:1-5
1 Then Job answered and said,
2 I have heard many such things: miserable comforters are ye all.
3 Shall vain words have an end? or what emboldeneth thee that thou answerest?
4 I also could speak as ye do: if your soul were in my soul's stead, I could heap up words against you, and shake mine head at you.
5 But I would strengthen you with my mouth, and the moving of my lips should asswage your grief.
Job said that he would comfort them, because what he's going through right now is stone-cold proof that people suffer who haven't done anything particularly wrong to deserve it, and often people suffer wildly disproportionately in relation to the sins that they commit.
Towards the end of the book of Job, God shows up, and rebukes Job's friends:
Job 42:7
7 And it was so, that after the Lord had spoken these words unto Job, the Lord said to Eliphaz the Temanite, My wrath is kindled against thee, and against thy two friends: for ye have not spoken of me the thing that is right, as my servant Job hath.
If there's one lesson that anyone can glean from the book of Job, it's that the causes of suffering are often mysterious, and only God knows the exact, precise reason that an individual suffers.
You, as a human being, most often have no idea for certain why so-and-so is going through whatever they are going through. Speculating that those suffering are doing so because of their own sins in a past life, then, may lead you to place blame squarely on an innocent person.
Karma, in light of the Bible, is a supremely evil false doctrine. It was invented by wicked men trying to understand the world, while rejecting divine revelation.