The Arabic word ‘Khamr’ signifies any alcoholic drink which causes intoxication. It also refers to every other substance the use of which obscures the intellect. The Arabs during the period of ignorance were very fond of wine and drinking. To eradicate this pervasive evil from the society, Allah SWT prohibited it in measured stages through several verses revealed at different times. First, He made it clear to them that the harm of drinking wine is greater than its benefit; next, He told them not to come to Salat while intoxicated; and finally He revealed this verse which prohibited it totally saying, “O you who believe! Truly, intoxicants and gambling and divination by arrows are an abomination of Satan's doing: avoid it in order that you may be successful. Assuredly Satan desires to sow enmity and hatred among you with intoxicants and gambling, and to hinder you from the remembrance of Allah and from Salat. Will you not then desist?” [5:90].  

Root of Evil:  The prohibition of use of intoxicants in Islam draws its validity from the fact that it affects a person mental state and prevents one from thinking clearly and rationally. Islam takes an uncompromising stand in prohibiting intoxicants, regardless of whether the amount is little or much.  Allah SWT mentions the harmful effects of use of intoxicants on the society, namely, the breaking of relationships, ensuing enmity and hatred, jeopardizing one’s safety and health, in addition to the harm they do to one’s soul by causing him to neglect the religious obligations and disobeying Allah’s commands.   Allah SWT says, "They ask you (O Muhammad ) concerning alcoholic drink and gambling. Say: "In them is a great sin, and (some) benefit for men, but the sin of them is greater than their benefit." And they ask you what they ought to spend. Say: "That which is beyond your needs. Thus Allah makes clear to you His Laws in order that you may give thought." [2:219].    Prophet PBUH said, “…don’t drink wine for it is the key to every evil” [Tirmidhi].

Other Intoxicants:  Khamr  is not only alcoholic beverages, but all that which intoxicates and alters the mind, impairing its faculties of thought and perception; in whatever amount or form or under whatever name it may appear (like: narcotics, heroin, other derivatives,...).  Prophet PBUH said, "Khamr is that which befogs the mind" [Bukhari].   This provides a criterion for defining what falls under the prohibited category of Khamr.  Prophet PBUH was once asked about certain drinks made from honey, corn, or barley by the process of fermenting them until they became alcoholic. He PBUH replied, "Every intoxicant is khamr, and every khamr is Prohibited" [Muslim].

Dying when Addicted: Prophet PBUH said, “He who drinks wine in this world and dies while he is addicted to it, not having repented,  will not be given a drink in the Hereafter" [Muslim].   Prophet PBUH said, "If one who is addicted to intoxicants dies, he will meet Allah SWT in the same condition as an idolater" [Ahmad].  Allah SWT says, “…and do not throw yourselves by your own hands to destruction…” [2:195]  

Trading in Alcohol:  Prophet PBUH did not only prohibited the drinking of alcohol, but he also forbade trading in it. He PBUH cursed ten people in connection with wine: “the wine-presser, the one who has it pressed, the one who drinks it, the one who conveys it, the one to whom it is conveyed, the one who serves it, the one who sells it, the one who benefits from the price paid for it, the one who buys it, and the one for whom it is bought” [Tirmidhi].

Prayer Not Accepted: Prophet PBUH said, "If anyone drinks wine Allah will not accept prayer from him for forty days, but if he repents Allah will forgive him. If he repeats the offence Allah will not accept prayer from him for forty days, but if he repents Allah will forgive him. If he again repeats the offence Allah will not accept prayer from him for forty days, but if he repents Allah will forgive him. If he repeats it a fourth time Allah will not accept prayer from him for forty days, and if he repents Allah will not forgive him, but will give him to drink of the river of the fluid flowing from the inhabitants of Hell" [Tirmidhi].