Sufism cannot be called a religion because it is free from principles, distinctions and differences, the very basis on which religions are founded; neither can it be called a philosophy, because philosophy teaches the study of nature in its qualities and varieties, whereas Sufism teaches unity. Therefore it may best be called simply the training of the view.
The word Sufi implies purity, and purity contains two qualities. Pure means unmixed with any other element, or in other words that which exists in its own element, unalloyed and unstained. The second quality of purity is great adaptability.
Such is also the nature of the Sufi. In the first place he purifies himself by keeping the vision of God constantly before him, not allowing the stains of earthly differences and distinctions to be mirrored upon his heart, nor good or bad society, nor intercourse with high- or low- class people. Nor can a faith or a belief ever interfere with his purity.
The Sufi shows his universal brotherhood in his adaptability. Among Christians he is a Christian, among Jews he is a Jew, among Muslims he is a Muslim, among Hindus he is a Hindu; for he is one with all, and thus all are with him. He allows everyone to join in his brotherhood, and in the same way he allows himself to join in any other. He never questions, "What is your creed or nation or religion?" Neither does he ask, "What are your teachings or principles?"
Call him brother, he answers brother, and he means it. With regard to principles, the Sufi has none, for sweetness may be beneficial to one and harmful to another. Thus it is with all principles, good and bad, kind and cruel. If we ask a soldier to be merciful during the battle, he will at once be defeated. This shows that everyone has his own principle for each action or situation. One person may believe in a certain principle, while another may hold quite a contrary opinion. What one person may call good another may call bad. One says a certain path is the right one, while another takes the opposite direction. The Sufi, instead of becoming centered in his likes and dislikes and limiting himself to a certain faith or belief, reasoning out right and wrong, focuses his view on that of another, and thus sees the reason why he believes and why he does not, why something is right to one and wrong to another. He also understands why that which is called good by some people may be called bad by others, and thus by keeping his point of view under control he arrives at the true height of wisdom."
An excerpt from an article entitled: "The Freedom of the Sufi" in THE MESSAGE Vol. IX No. 3 May-June, 1983