In this book, we are going to talk about a voice that always inspires justice, good manners, humility, honesty, sincerity, and all that is most righteous. This voice, though you may be unaware of it, is always with you wherever you go. 'To whom does this voice belong?' you may then ask. Well, this voice belongs to you, it is within you, it is the voice of your conscience… The word 'conscience' is very common and much used. However, the actual meaning of the word, its importance in the deen (religion), how a really conscientious person behaves and what separates him or her from other people are not so well known in general. Conscience is limited to the meaning acknowledged by society. According to popular belief, those who do not, for example, dump rubbish in the streets, who give money to beggars and take care of stray animals are shown as examples of conscientious people. However, the actual meaning of the word 'conscience' is far more subtle and comprehensive than the meaning attached to it by society. The purpose of this book is to introduce the real meaning of conscience as exemplified in the Qur'an and to draw attention to how a conscientious person thinks, what kind of insight and understanding he or she possesses, and the importance of conscience in life after death. We will provide you with the necessary information to identify the voice of your conscience, and distinguish it from the other voices and suggestions coming from within you. We will also explain some of the things your conscience may make you think and do and how someone who acts upon his conscience can attain the purest state. The main purpose of this book is not only to inform, but also to call out to people's conscience in order to spur them into action, encourage them to live the rest of their lives by their conscience, and show them how lost they will be if they fail to do so.