According to Imam Abu'l Qasim Abdulkarim ibn Hawazin al-Qushayri (d. 465A.H), "Ma'arifa is the attitude of the man who acknowledges God in His Names and Attributes, who is further sincere in his actions, who frees himself from the blame worthy traits of character and from weaknesses, who at all times stands at the gate and continuously lets his heart dwell with God, so that God would grant him friendly reception, and who in all his conditions is sincere and free from influence of his self, and who in his heart does not listen to any influence which calls him in a direction other than that to God.

  When thus he has become alien to creature, free from the frailties of self, liberated from the bonds of human contacts and mental distractions, when in his innermost being he is in continuous communion with God, and at each moment truly comes back to God, when he has knowledge of God by receiving His secrets concerning the operating of His decrees, then he will be called ARIF and his condition will be called MA'ARIFA ".

SOURCE :- 'Al-Qushayri' s Epistle On Sufism.. Risalatul-Qushayriyya fi ilm al-'' Tasawwuf '.