It is harmful to the Deen, health, environment, family, brotherhood and social relations, property, etc. The following sections will briefly outline some of its harms and evils. To The Deen Smoking spoils a person's acts of worship and reduces their rewards. For instance, it spoils the prayer, which is the pillar of Deen. Thus, a smoker is in between two options, either to harm the praying people and the angels with his foul smell, or miss the prayer in jama'ah.
Smoking also spoils fasting.
Fasting is very hard for the smoker. As soon as the day is over, he hastens to break his fast on an evil cigarette instead of sweet dates or pure water. Ramadan, a smoker is reluctant to fast on other days. Thus he loses the great reward of those who fast even one day in Allah's way. No one can deny the harm of smoking to the human body.