Finding God by Serving Mankind :

Prophet Mohammed (Sal-am) said: God will say, ‘Son of Adam, I fell ill but you did not visit Me.’ He will say, ‘O Lord, and how could I have visited You! You are the Lord of the worlds!’ He will say, ‘Did you not know that My so and so servant had fallen ill and you did not visit him? Did you not know that had you visited him you would have found Me with him?’‘Son of Adam, I asked you for food but you did not feed Me’. He will say, ‘O Lord, how could I have fed You! You are the Lord of the worlds!’ He will say, ‘My so and so servant asked you for food and you did not feed him? Did you not know that had you fed him you would surely have found that with Me?’‘Son of Adam, I asked you to give Me to drink but you did not give Me.’ He will say, ‘O Lord, how could I have given you to drink! You are the Lord of the worlds!’ He will say, ‘My so and so servant asked you to give him to drink and you did not give him. Had you given him to drink you would surely have found that with Me’. (Muslim: Abu Hurayrah)