It's difficult to summarize the Sufi tradition, or any religion really, so I'll do my best here. Sufism is a mystical branch of Islam, though some Sufis argue that they came before the Prophet Mohammed, while others find that offensive. As one website said, Sufism "has its roots in the Qu’ran and the Islamic tradition, but at the same times encompasses the universal mysticism that we see in other spiritual traditions. The essence of Sufism is the simple path of loving God. The Sufi Masters sing of the all pervading love which inundates their being when they become one with their “beloved”. If there is just one goal of Sufism; it is to overcome the attachment to the binding ego and attain liberation through realising one’s identity with God."
Reading Hafiz and Rumi, I am always so moved by the simple, divine love they express for God, which always make God seem so close and intimate, like a best friend or lover. In fact, in Sufi poetry we often find God referred to as Friend, Beloved, Father, Mother, the Wine seller, the Problem giver, and the Problem solver. As the website states: "This ambiguity in describing God served a dual purpose. Firstly it made it difficult for his poetry to be censored for its unorthodox mystical ideas. It also illustrates the inherent difficulty a poet has in describing the nature of God. The infinite is beyond all name and form, how can the poet describe that which is beyond words?"
The website goes on to say: "The Sufi masters believed that outer religious forms were useless, unless they inspired the inner devotion. Poetry was their tool to poke fun at the pompous and arrogant. They took great delight in exposing hypocrisy, pride and vanity."
Finally, here is a quote from the Sufi commentator Quashayri:
Sufism is entry into exemplary behavior and departure from unworthy behavior. Sufism means that God makes you die to yourself and makes you live in him. The Sufi is single in essence; nothing changes him, nor does he change anything. The sign of the sincere Sufi is that he feels poor when he has wealth, is humble when he has power, and is hidden when he has fame. Sufism means that you own nothing and are owned by nothing.Enjoy a short clip of Whirling Dervishes dancing the sema below. A quick note about the sema, or Dervish dance. The Dervishes (or semazens) and begin twirling. This represents the birth of humanity. The sikke is the slender earth-colored headdress which symbolises the tombstone of the ego. The hırka is the long black cloak representing the tomb. The tennure is the full skirted long gown depicting the shroud. As the dervishes enter the circle their arms are crossed across their chest. In this position they signify the oneness of God. During the sema their arms are extended with the right hand opened upward, receiving from God, and the left hand turned downward, giving to humanity and keeping nothing for themselves.
Sufism means entrusting the soul to God most high for whatever he wishes. Sufism means seizing spiritual realities and giving up on what creatures possess. Sufism means kneeling at the door of the Beloved, even if he turns you away. Sufism is a state in which the conditions of humanity disappear. Sufism is a blazing lightning bolt.
--Quoted in Sufism: An essential introduction to the philosophy and practice of the mystical tradition of Islam, by Carl W. Ernst, PhD)
And now, I close with a little quote from Hafiz:
"A poet is someone
Who can pour Light into a spoon,
Then raise it to nourish
Your beautiful parched, holy mouth."
Be sure to check out the video below for a small glimpse into the sema ritual.
Or an even better one here (which I couldn't embed).