Those who knew the messenger when they saw him, recognized him in whatever form or guise; those who could only see the coat went astray. To the Sufi, therefore, there is only one teacher, whatever name he may be given at different periods in history; and he comes constantly to awaken humanity from the slumber of this life of illusion and to guide man onward towards divine protection. As the Sufi progresses in this view he recognizes his Master not only in the holy ones, but in the wise and in the foolish, in the saint and in the sinner, and he has never allowed the Master, who is the one and only Master and who alone can be and who ever will be, to disappear from his sight.