Who is a Believer
The Messenger of Allah [s] said:
“Whoever is pleased with his good actions and displeased with his bad actions is a faithful.”
How happy you feel when you see a poor needy man and help him with some money.
How elated you are if you recite some verses of the Holy Qur’an at dawn.
Your sense is of great satisfaction, when you do an action which pleases your parents.
All are good deeds which you love because you are a believer and are happy to do them and always think of doing them.
Conversely, people who do evil deeds, are emotionally disturbed in feeling pleased by cheating people, or lying to them or stealing something, or doing something that is forbidden. He gives up prayer without feeling himself a sinner because he loses his conscience. He does not judge himself for his irresponsibility or question why he has done such evil deeds.
Surely, there is no truthful belief in the heart of such a man.
Surely, the true believer is he who suffers in case he has committed a mistake, and finds himself guilty in the case of committing an evil action. Consequently, he asks Allah’s forgiveness and then repents. He apologizes to the people whom he has wronged.
The Messenger Muhammad [s] says:
“The faithful is he whose evil deeds displease him.”
This Prophetic tradition means that he is displeased with himself when committing a misdeed and feels a strong aversion to doing it again.
He who likes doing evil deeds cannot be good but he who loves doing good deeds shows his virtuous nature and can only be good.
As an example we can compare flies with bees; flies, on the one hand live in dirt and gather germs, even from dead animals. In this way, they carry sickness to people, causing people to dislike them and spray poisonous substances to kill them and prevent the spread of disease.
Bees, on the other hand love beautiful flowers, from which they gather pollen, which gives us honey as a useful nourishment for our bodies. Therefore, people approve of bees and even breed them and safeguard their lives.
People feel happy and satisfied by doing good acts and giving charity, but dislike doing evil deeds, which causes harm, This feeling in us is called conscience.
The Islamic religion wants to bring out the conscience in us in order that we do beneficial acts and avoid committing evil deeds and actions. The aim is to speed us on our way to becoming true faithfuls.
 Bihbodi, Sahih al-kafi, p.100.