A verse in the Quran speaks about charity: "Those who give to others what has been bestowed upon them with their hearts trembling at the thought that they must return to their Lord." (23:60) When you give something to a person you are the giver and he is the taker. You should develop pride. You may think: 'I am in a position to give, while he is in a position to take.' This should develop arrogance. But the Quran tells us that it should be the opposite. A person should have fear in his heart while giving to others. When a person gives to the poor, orphan, or the needy, he sees his own picture in them. He remembers that he too will be needy in the Hereafter. 
In this world the other person is needy, but in the Hereafter, I will become needy. This makes your heart tremble. For such a person, his charity becomes a prayer: 'O God, one day I will be standing before you as a needy person. Do not deprive me on that day.' This verse tells us that a believer draws lessons from every event. In Madinah, a person once began to hit his servant. When the Prophet saw this he said: "God has more power over you than you have over your servant."
The Prophet gave a lesson: when you see a weak person, remember that you too will one day stand before God in complete weakness.  The above person then stopped hitting his servant and gave him his freedom. The Quranic verse tells us what kind of a giver a true believer is. He sees his own picture when he is giving to the needy. So, his giving becomes a prayer. Apparently, he is giving money to a person. But from within he is praying to God: 'O God, one day I will also be standing before You in need. Do not leave me deprived on that day.' This verse gives the description of a true believer.