A man loves a woman who is living in a distant place. His love causes him to be thinking of her all the time; and he cannot eat and he cannot sleep. His thoughts are only on his separation from her and he continually longs for her. When this longing becomes too great, he either goes to her or he compels her to come to him. This is called Ishk-e-Mijazi or physical love.
To love God one should think of God, long for God and suffer the fire of separation until one’s longing reaches its utmost limits, and God the Beloved comes to the lover and his thirst is quenched in union with God. This love is called Ishk-e-Haqqiqi, and is a gift from God.
But one who obeys the Master who is One with God, need not suffer these things, for in obedience is the Grace of the Master.
-The Everything and Nothing, p6