Drunkenness is sin in and of itself… "nor drunkards... shall not inherit the Kingdom of God," according to the teaching of the Apostle (1 Cor. 6:10). And Christ says, And "take heed to yourselves, lest at any time your hearts be overcharged with surfeiting, and drunkenness" (Lk. 21:34). This is the cause of so many and serious sins. It brings about the quarrels, fights, and bloodshed, and murders that follow upon it. It is rough talk, blasphemy, and cursing. It causes disappointment and offence to neighbor. It teaches lying, flattery, seizure of the things of others so as to somehow satisfy the passion. It ignites anger and wrath. It makes people cast themselves into impurity as swine into the mire.
In a word, it makes a man a beast, and the rational irrational, so that not only the inward condition but also the outward appearance of a man often changes. Wherefore St. John Chrysostom says, "The devil loves nothing like luxury and drunkenness" (Homily 58 on St. Matthew), because nothing fulfils his evil will as does a drunkard.
Saint Tikhon of Zadonsk