NAHJUL BALAGHA
SERMON 50
The basis of the occurrence of evils are those desires which are acted upon and the orders that are innovated. They are against the Book of Alláh. People co-operate with each other about them even though it is against the Religion of Alláh. If wrong had been pure and unmixed it would not be hidden from those who are in search of it. And if right had been pure without admixture of wrong those who bear hatred towards it would have been silenced. What is, however, done is that something is taken from here and something from there and the two are mixed! At this stage Satan overpowers his friends and they alone escape for whom virtue has been apportioned by Alláh from before.