Smoking is the practice of purposefully inhaling smoke from burning materials, typically a dried plant such as tobacco. The most common form today is cigarette smoking. While smoking has been a habit of many ancient and modern men, it fell out of favor due to association with various cancers - especially lung cancer.
There are various negative effects of smoking. Every 15 cigarettes someone smokes will cause a mutation in their body, and mutations are how cancers start. The poisons from the tar in cigarettes enter the smoker's blood, making the blood thicker, and increase chances of clot formation. It also increases the blood pressure and heart rate, making their heart work harder than normal and narrows the arteries, reducing the amount of oxygen-rich blood circulating to your organs. Smoking doubles one's risk of having a heart attack, and those who smoke you have twice the risk of dying from coronary heart disease than lifetime non-smoker.  Smoking harms the immune system and can affect nearly every organ of the body.  Tobacco smoking kills more than six million people every year, translating to one smoking-related death every five seconds. Which is a million more deaths than occurs each year as a result of HIV, tuberculosis, and malaria combined. For out every five deaths in American are accounted by smoking, as it kills more than 480,000 Americans die each year. 
Other Smoking Methods
Bidis and hookahs have become popular alternatives to smoking cigarettes, and people seem to think they are less harmful than regular cigarettes. However, the truth is that hookah smoke still delivers addictive nicotine, and bidis actually have more nicotine than cigarettes. 
Smoking and cancer
Smoking is a causal factor for various cancers such as lung cancer and cancers of the esophagus, larynx, mouth, throat, kidney, bladder, liver, pancreas, stomach, cervix, colon, and rectum, as well as acute myeloid leukemia.
Religion, irreligion and smoking
See also: Atheism and smoking
The abstract of the 2012 International Journal of Psychiatry in Medicine journal article entitled Religion and smoking: a review of recent literature indicates:
|“||Tobacco smoking and exposure to secondhand smoke are a major threat to human health worldwide. The effort to prevent tobacco use should be regarded as an important public health strategy. Given the significance of religion and spirituality in the daily life of more than 90% of the world's population, the relationship of religion and smoking should be seen as a critical research area. Religions are many and varied, but most value human well-being highly and so do not approve of tobacco use, even though they do not prohibit it entirely. In recent years, researchers have shown more interest in the subject of religion and health, including drug and tobacco use. Differences of focus and methodology notwithstanding, most studies have ascertained a deterrent role for religion as regards tobacco use, and several mechanisms have been proposed to explain the negative relationship between religion or spirituality and smoking.||”|
The 2017 journal article Smoking and Religion: Untangling Associations Using English Survey Data published in the Journal of Religion and Health indicates: "Highest levels of smoking characterise people not professing any religion... An association between smoking and the absence of a religious affiliation is sustained. An understanding of the association between smoking and religion is essential to the development of tobacco control programmes."}}
- Smoking cessation fact sheet, National Cancer Institute
- [https://www.cdc.gov/tobacco/campaign/tips/diseases/cancer.html CDCTips From Former Smokers ®Diseases/Conditions Featured in the Campaign Smoking and Cancer], Centers For Disease Control and Prevention
- How smoking causes cancer, Cancer Research, UK
- [Religion and smoking: a review of recent literature.] by Garrusi B1, Nakhaee N., International Journal of Psychiatry in Medicine , 2012;43(3):279-92.
- *Smoking and Religion: Untangling Associations Using English Survey Data, J Relig Health. 2017