Do not praise your own faith so exclusively that you disbelieve all the rest. If you do this, you will miss much good. Nay, you’ll fail to realize the real truth of the matter: God, the omnipresent and omniscient cannot be confined to any one creed, for he says in the Qu’ran, ‘For wheresoever you turn, there is the face of Allah.’ Everybody praises what he knows. His God is his own creature, and in praising it, he praises himself. Consequently, he blames the beliefs of others, which he would not do if he were just– but his dislike is based on ignorance.
The quotation comes from chapter 10 of his work The Bezels of Wisdom.