They recite their sacred books, although the fact informs me that these are a fiction from first to last. O Reason, thou (alone) speakest the truth. … - al-Ma'arri

The world holds two classes of men; intelligent men without religion, and religious men without intelligence.

Sometimes you may find a man skillful in his trade, perfect in sagacity and in the use of arguments, but when he comes to religion he is found obstinate, so does he follow in the old groove. Piety is implanted into human nature; it is deemed a sure refuge. To the growing child, that which falls from his mother's lips is a lesson that abides with him all his life. Monks in their cloisters and devotees in their mosques accept their creed just as a story is handed down from him who tells it, without distinguishing between a true interpreter and a false. If one of these had found his kin among the Magians, or among the Sabians, he would have become nearly or quite like them.

This world is such an abode that if those present here
Have their wits entire, they will never weep for the absent ones.