Imam Ghazali on Causes of Sin
1. First cause
The punishment of sin is not presently seen and lies in the womb of future.
2. Second cause
It is the present taste of the greed which leads to the sinful act. His habit assumes strong form owing to love for sin. Habit is the fifth nature. The present taste over nature predominates over the future tastes. For this reason God says, “Never rather you love the present and discards the future.” God says: “Rather you love the pleasure of the world’s life.”
The gravity of this affair is rendered clear from this word of the Prophet (S) who said:
“Paradise is surrounded by unpleasant things and Hell by greed.”
Prophet (S) said:
“God said to Gabriel after creation of Hell: Go and look at Hell. He saw it and said: By Thy glory, nobody will enter it if he hears of it. Then God surrounded it with things of greed and said to him: Go and look at it. Gabriel saw it and said: By Thy glory, I fear that there will be nobody who will not enter it.
He created Paradise and said to Gabriel: Go and look at it. Gabriel saw it and said: By Thy glory, he who hears of it will want to enter it. Then he surrounded it with unpleasant things and said: Go now and see it. He saw it and said: By Thy glory. I fear that nobody will enter it.”
Greed is connected with the present and punishment with the future. There are two reasons for the commission of a sin though the basic faith remains alright. He who becomes impatient of thirst and drinks icy water during illness does not deny the basic science of medicine and also does not deny that it is injurious to his health, but the greed of his thirst becomes then strong and he becomes unable to face the difficulty of patience.
3. Third cause
There is no such a sinner who does not wish to expiate his sins by repentance and good works, but he makes delay to make repentance and expiation owing to the prevalence of long hope in him.
4. Fourth cause
There is no such believer who does not cherish hope for forgiveness of his sins. He awaits for pardon relying on the mercy of God after committing sins.
For these four causes a believer is engaged in committing sins over and again even though his basic faith remains alright. It is true that for the fifth reason, defect enters into his basic faith.
To entertain doubt about the Prophet-hood of Muhammad (peace be upon him). This is infidelity.