"Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour." - 1 Peter 5:8
"And be not drunk with wine, wherein is excess; but be filled with the Spirit." - Ephesians 5:18
For those of us that have accepted the Gospel of salvation (1 Cor. 15:1-4), we still struggle with our flesh in a constant battle (Romans 7:14-25) and we struggle against spiritual forces (Eph. 6:12). When we allow ourselves to become intoxicated, we open the door for Satan to attack us. We put ourselves into a position where we cannot defend ourselves physically or spiritually.
Look at what Paul commands us to do in order to survive in this world:
"Put on the whole armour of God, that ye may be able to stand against the wiles of the devil.For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; And your feet shod with the preparation of the gospel of peace; Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. And take the helmet of salvation, and the sword of the Spirit, which is the Word of God: Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints." - Ephesians 6:11-18
Drunkenness is the willingness to give our minds and bodies over to Satan instead of God; it is choosing the false, temporary pleasures of the world over the true joy that can only be found in Jesus Christ.
Can a drunk Christian effectively put on armor?
Can a drunk Christian effectively share the Gospel?
For an unsaved person, intoxication is giving the Devil more of an opportunity to distract them from coming to Christ.
For a saved person, intoxication is being conformed to this world and ruining their testimony.
Next work of the flesh: revellings