Zikr is an Arabic word; it means remembrance. Zikrullah simply means to remember God. It is not a formal act, but rather a spontaneous one, which comes as naturally to one who has come to know God as singing is to a bird.
A spiritual upheaval of the utmost intensity occurs in one who discovers God in all His power and glory. Suddenly, God is forever in one’s heart and thoughts. One’s constant remembrance of God expresses itself in multifarious forms. Sometimes it is an inward experience–- a tingle of joy, a shiver of fear that creeps down one’s body as thoughts of God fill one’s mind. Sometimes one enters into a spontaneous outpouring of thanksgiving and adoration. It is this state of mind that constitutes remembrance of God, whether it is expressed in the form of words of praise or silent thoughts.
Sometimes one looks at outer space in all its infinite vastness, and ponders on the stars and constellations spread out there. “How great must be the Lord who has arranged this marvellous display and runs it with such superb finesse;” such is one’s reaction to the sight spread out before one. Sometimes one gazes at rivers, trees and mountains, and one’s heart is touched by their beauty by the very meaningfulness of their existence. If one has discovered God, everything around one reminds one of Him, sparking off a never-ending litany of remembrance in one’s mind and heart.”
Remembrance of such a being is bound to be the greatest of all human experiences; there are no words that fully express the profundity of that feeling.