To the first belongs the one who rejoices at blessings, not in respect to their Bestower or Originator, but in respect to his pleasure in them. This man belongs to the forgetful (al-ghafilun), and God's words hold true for him: "Until, when they rejoiced in that which they were given, We seized them suddenly." (The Quran 6:44)
To the second category belongs the one who rejoices at blessings or as grace from Him who brought it to him. God refers to him with His words: "Say: In the grace of God and in His mercy, in that they should rejoice. It is better than that which they hoard." (The Quran 10:58)
To the third category belongs the one who rejoices in God. Neither the exterior pleasure of blessings nor their interior graces divert him. Instead, his vision of God, his concentration on Him (al-jam' 'alayh), divert him from what is other than He, so that he contemplates only Him. God refers to him with His words, "Say, Allah! Then leave them prattling in their vain talk." (6:91) God revealed to David, "O David, say to the truthful: Let them rejoice in Me, let them find joy in My invocation!"
May God make your joy and ours in Him and in the contentment that comes from Him; may He put us amongst those who understand Him; May He not put us amongst the forgetful, mindless; and may He voyage with us in the Path of the God-consciousness with His Grace and Generosity! Amen
~ From Shaykh Ahmad ibn Ataillah as-Sakandari's al-Hikam