Sufism is less an Islamic sect than a mystical way of approaching the Islamic faith. It has been defined as "mystical Islamic belief and practice in which Muslims seek to find the truth of divine love and knowledge through direct personal experience of God."
These terms evolved in Western languages in the early 19th century and derive from the Arabic term for a mystic, sufi, which in turn derives from suf, “wool.” This likely refers to the woollen garment of early Islamic ascetics.Sufism has been a prominent movement within Islam throughout most of its history. It grew out of an early ascetic movement within Islam, which sought to counteract the worldliness that came with the rapid expansion of the Muslim community.
These early Sufis led a life of strict obedience to Islamic scripture and tradition and were known for their night prayers. Many of them concentrated their efforts upon tawakkul, absolute trust in God, which became a central concept of Sufism.
Another century or so later, a new emphasis on love changed asceticism into mysticism. This development is attributed to Rabi'ah al-'Adawiyah (d. 801), a woman from Basra who formulated the Sufi ideal of a pure love of God that was disinterested, without hope for Paradise or fear of Hell.
Sufi beliefs are based firmly in orthodox Islam and the text of the Quran, although a few Sufi teachers have strayed too close to monism or pantheism to remain within the orthodox fold.
The core principles of Sufism are tawakkul (absolute trust in God) and tawhid (the truth that there is no deity but God). Tawhid is rich in meaning for mystics: it has been interpreted by some as meaning that nothing truly exists but God or that nature and God are but two aspects of the same reality.
The love of God for man and the love of man for God are also very central to Sufism, and are the subjects of most Islamic mystical poetry and hymn.