Today Sufism is a name without a reality. It was once a reality without a name. In the time of the Prophet, this name did not exist, but its reality was inside of everyone. Now the name exists without the reality. In the first 3 generations of Islam mysticism was too general too have a special name. But when worldliness spread and men tended to become more and more bound up with the ties of this life, those who dedicated themselves to the worship of God were distinguished from the rest by the title of Sufis.
– Martin Lings