The book Sinology by Mohsen Qaraati has been published in the publications of the Cultural Center of Lessons from the Qur'an. In the word sin, it refers to an act that is against the orders of God and Islam. The religion of Islam always prevents people from committing sins, and for committing any sin, it has a punishment. Therefore, it is obligatory for Muslims to know the sin and the reasons for committing it. This book deals with sin and the actions that cause it, its consequences and effects, the fields and ways of recognizing and controlling and repenting of sin. Sinology examines the reasons and contexts of sin and everything that causes sin, and recounts the social, cultural, family, economic, political, and psychological causes that have an impact on sin. The author describes and recognizes sins and the border between good and bad actions. He believes that knowing these boundaries prevents sin. The last chapter of the book recounts the stages of repentance and how to do it using the traditions and verses of the Quran. Sinology was written based on the words of Mr. Qaraeti in the program "Lessons from the Qur'an" on the Islamic Republic of Iran Radio and Television. The main titles of the book include: Publisher's statement; preface; 1- The meaning of sin; 2- Words of sin in the Quran; 3- The words of sin in narrations; 4- Another way to recognize sin; 5- The cursed in the Qur'an; 6- The cursed in the narrations; 7- The army of wisdom and ignorance; 8- Types of sin; 9- Classification of sins in narrations; 10- The criteria for recognizing major sins from minor ones; 11- The cases of turning a small sin into a big one; 12- The sin of elders from the point of view of the Qur'an; 13- Parable of the uncommitted scientist in the Qur'an; 14- The sin of elders from the point of view of narrations; 15- Key sins; 16- Danger alarm; 17- Grounds of sin in human existence; 18- The grounds of the origin of sin; 19- cultural and educational contexts of sin; 20- family grounds of sin; 21- economic aspects of sin; 22- Social aspects of sin; 23- Psychological aspects of guilt; 24- Political aspects of sin; 25- justification and reasoning for sin; 26- Various justifications; 27- Theological justifications; 28- Political justifications; 29- Social justifications; 30- Psychological explanations; 31- Cultural justifications; 32- economic justifications; 33- military justifications; 34- knowing the boundaries of sin; 35- Asceticism and leaving the world; 36- Preference of important over important; 37- Attention to all values; 38- The levers that prevent sin; 39- thinking about various matters; 40- Attention to the presence of God everywhere; 41- Self-knowledge and attention to personality; 42- Faith in resurrection; 43- Width of actions; 44- Remembering death; 45- Fear of God and fear of the consequences of sin; 46- The role of worship in preventing sin; 47- Islam's treatment of sinners; 48- Social discipline; 49- Narratives and dealing with the sinner; 50- The curse of Imam Sadiq, peace be upon him; 51- Dealing with Imam Kazem, peace be upon him; 52- Jurisprudential treatment of the sinner; 53- Effects and consequences of sin; 54- The worldly punishments of sin; 55- Hereafter punishments of sin; 56- Frustration and nullification of good deeds; 57- The effects of sin on the soul; 58- Various effects of sin; 59- Repentance and purification; 60- Repentance from the point of view of narrations; 61- Atonement for sin; 62- Atonement for sin from the point of view of the Qur'an; 63- Atonement for sin from the point of view of narrations; 64- Coordination of compensation with sin; 65- A few stories related to atonement for sin; 66- Notes and tickets