What does it mean to be filled with the Spirit?

I am preaching this Sunday on Ephesians 5:18 "And do not get drunk with wine, for that is dissipation, but be filled with the Spirit." When I asked most people that question, they told me something to the effect of - walking in the Spirit (Gal 5:16), spending a lot of time reading/obeying/studying God's Word (Col 3:16), and being influenced/led by the Holy Spirit in your life. And this was my perspective until I spent a lot of time studying Eph 5:18 this week.

Paul prays in Eph 3:16-19 that Christians would be strengthened with power through the Holy Spirit so that Christ may dwell in your hearts through faith. And that we would understand the breadth, length, height, and depth of the love of Christ which surpasses knowledge so that we would be filled up to all the fullness of God.

It is God's design that believers would be filled up to all the fullness of God. Specifically, that we would be filled with the incomprehensible love of Christ that is immeasurable, having infinite breadth, length, height, and depth. And not only Christ's love, but also we are to be filled up with God's infinite majesty, glory, and holiness. It is God's command that we be filled with the very character of God, all that makes God, God. Be filled with the Holy Spirit.

Isn't that amazing? How could God fill me with all the fullness of God? That is grace. And this is the culmination of God's design for the church (Eph 1:23). And of course, when we are filled with the fullness of God, we will walk in the Spirit, bear fruit, and be led by His Word. God is so good.