not addicted to wine or pugnacious, but gentle, peaceable, free from the love of money.
1 Timothy 3:3

For the overseer must be above reproach as God’s steward, not self-willed, not quick-tempered, not addicted to wine, not pugnacious, not fond of sordid gain, …
Titus 1:7
(emphases mine)

An elder must always be ready to engage in ministry. This includes sharing the gospel, ministering to his flock in the midst of trials, demonstrating hospitality, protecting the flock, teaching, etc. His mind must always be clear so that he can serve the Lord responsibly.

Paul reminds us that all Christians must be careful in this regard.

And do not get drunk with wine, for that is dissipation, but be filled with the Spirit, speaking to one another in psalms and hymns and spiritual songs, singing and making melody with your heart to the Lord; always giving thanks for all things in the name of our Lord Jesus Christ to God, even the Father; and be subject to one another in the fear of Christ.
Ephesians 5:18–21

Dissipation is characteristic of a person who is reckless and irresponsible. Rather than being controlled by alcohol, Paul reminds believers that they are to be controlled by the Spirit of God. The result of such control is appropriate ministry to one another and thankfulness to God.

Peter emphasizes the need for believers to be of sober spirit.

Be of sober spirit, be on the alert. Your adversary, the devil, prowls around like a roaring lion, seeking someone to devour.
1 Peter 5:8

Carelessness in regard to alcohol can result in very serious implications. If an elder cannot think with biblical clarity, he cannot serve with biblical precision. Additionally, an elder must live a life that sets a pattern for others to follow.

…nor yet as lording it over those allotted to your charge, but proving to be examples to the flock.
1 Peter 5:3