The Sufi school of thought

Sufism is a mystical Muslim school of thought and aims to find love and knowledge through direct personal experience of Allah. 

The externalities of tradition law is quite unsatisfactory if divorced from personal theology and experience. The mystical love poetry of Sufi poets is one form of expression. Recitation of the names of God and of Qur'an phrases is another form of devotion.

Many Sufi orders exist across the Muslim world.  

Links: International Association of Sufism
Islamic Studies, Islam, Arabic, and Religion