Paul is commanding the Ephesians to walk using God’s wisdom, not the worlds. When we do that we are redeeming the time, which means we need to make the most of every opportunity in reaching the lost. He wants them and us to know that being wise is understanding God’s will. In this case it is not being drunk with wine, which is not a good thing and is evil. He wants us rather to be filled with the Spirit which is letting God completely control us. These results are expressed in the next few verses as speaking the Word of God in communication with one another, being joyful, thankful, and submissive to others.
To be filled or controlled by the Spirit is to let God’s Word control you, dying to self, pursuing purity, confessing all known sin, surrendering to God’s will, and depending on His Power for all things. It is to live dominated by the mind of Christ, so that everything that you think or do flows through what the Word teaches and is in harmony with it.
Ephesian 5:15-21 See then that you walk carefully, not as fools but as wise, 16 redeeming the time, because the days are evil. 17 Therefore do not be unwise, but understand what the will of the Lord is. 18 And do not be drunk with wine, in which is dissipation; but be filled with the Spirit, 19 speaking to one another in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord, 20 giving thanks always for all things to God the Father in the name of our Lord Jesus Christ, 21 submitting to one another in the fear of God.