Can you compare the concept of forgiveness and cleansing of sins in Christianity, Hinduism and Islam?
This is a very important question. The concenpt of sin and of forgiveness is quite different in the three religions. Islam and Christianity are closer to one another, but still different in very important ways. Hinduism is quite different, as it is not a theistic religion.
It is not clear that Hinduism has a concept equivalent to the Christian idea of sin. It does have the idea of karma. Karma is like a cosmic substance that ties one to earthly existence. To the extent that one has karma, to that extent one is kept from going to a higher plane of existence and is more distant from brahman, which is the ultimate reality. There is no exact equivalent to sin because there is no personal God to sin against. If we sin at all, we sin against ourselves or the universe, but not against a separate “God.” Deepak Chopra, the most well known American spokesperson for Hinduism has said, “Sin is an illusion (maya).”
Hinduism also does not have a concept of forgiveness, for the same reason that it does not have the concept of sin or even of justice. Sin, justice and forgiveness involve the relationship between persons, but the ultimate goal of Hinduism is to lose one’s personhood and to be absorbed into the ultimate panteistic brahman. Atman (soul) is absorbed into brahman. Therefore, although Westerners use the word karma in a way almost synonymous with sin, this is a misnomer. Karma is eliminated by good deeds and by meditating and coming closer to God, but it is not forgiven. What would be similar between Hinduism and Christianity is that most of the things we would call sin would create “bad” karma, so what we consider sinful most Hindus would agree also should be avoided. In the end, Hinduism and Christianity have a rather similar morality, but the underlying meaning of that morality in the two religions is very different. To commit an immoral act in the Christian world view is to offend against a fellow person or against God, and such sinful acts need to be redeemed, restoring a right relationship. To commit an immoral act in Hinduism ties one more closely to physical things. It is to send one toward a lower state of existence. The wages of such karma is not death, but being tied to physical things for more lifetimes, assuming it requires one to be reincarnated more times.
As I already said, the concept of sin in Islam is more similar to that in Christianity, but it definitely is not identical. As a rule, nearly all of the things we would think of sinful in Christianity are also sinful in Islam/the Qur’an. Both in Christianity and in Islam to sin is to commit an act against a personal God to whom we must give account individually. However, there is a vast gulf between Isalm and Christianity with regard to the idea of forgiveness. In Christianity, the wages of sin are death (Romans 6:23). Such sin requires justice and God’s justice requires death. In Islam, sin brings on the wrath of Allah, but it is not clear that the wages of any individual sin is death. In Christianity, sin is forgiven by the substitutionary death of Jesus, as I am sure you know. “Therefore, there is now no condemnation for those who are in Christ Jesus, because through [the death of] Christ Jesus the law of the Spirit of life set me free from the law of sin and death.” (Romans 8:1). In the Christian covenant, when one is saved through the blood of Jesus, all one’s sins are completely washed away and forgiven. No good act can possibly bring about this forgiveness. The forgiveness is complete and unconditional.
There is nothing even remotely similar to this Christian idea in Islam. The Qur’an makes statements that are at least a little bit confusing. It is hard to say precisely what the Muslim teaching is on forgiveness. In Islam it is more a matter of mercy than of forgiveness. Many passages in the Qur’an show in stark terms the difference. For example, there is Sura 11:114, “Surely, good deeds take away evil deeds.” Salvation is gained through one’s effort (surat 40:9, 39:61, 7:43). Charity atones for sins (sura 2:271, 277). In Islam, the average Muslim does not anything like the assurance of salvation we have in Christianity. If one can be assured of going to heaven, it is according to one’s acts. For example, if a Muslim dies in jihad, fighting the pagans for Allah, then all of one’s sins are overweighed by this on act. Is this forgiveness? That is debatable at best.
So, as you can see, the Muslim, Hindu and Christian understanding of sin and forgiveness are quite different.
I hope this helps.