(27) It is related by Abu Imama that [once] a person asked the Apostle of God, “What is Faith?” The Apostle of God replied, “When you feel pleasure at a good act of yours and pain and sorrow at an evil act, you are a truthful Believer.”

- Masnad-I-Ahmad
Commentary.- It shows that one of the distinctive signs of Faith is that when a person performs a noble deed he feels joy in his heart at it, and when he commits a wicked deed, it makes him sad. As long as this subjective sense of right and wrong is present in a man it should be supposed that the spirit of Faith is alive within him and this feeling is its fruit and outcome.