[Lukongsimi]

To be a Christian is to have the Spirit of Christ. Romans 8:9: “You . . . are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.”

So, no one is a Christian if he does not have the Holy Spirit. Then in Ephesians 5:18, Paul addresses Christians who have the Holy Spirit. And we know that, by the way, because in chapter 1 he said, “You [my readers] . . . were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory” (Ephesians 1:13–14). Then he says in Ephesians 5:18–20,

And do not get drunk with wine, for that is debauchery, but [you Christians, who already have the Spirit] be filled with the Spirit, addressing one another in psalms and hymns and spiritual songs, singing and making melody to the Lord with your heart, giving thanks always and for everything to God the Father in the name of our Lord Jesus Christ.
In other words, being filled with the Spirit is a level or a quality of Spirit-empowering that sometimes is more, and sometimes less. For example, in Acts 4:31, it says that the Christians had gathered for prayer, “And when they had prayed, the place in which they were gathered together was shaken, and they were all filled with the Holy Spirit and continued to speak the word of God with boldness.”

So, one of the effects of this extraordinary, precious, sweet, powerful, unusual experience of being filled with the Holy Spirit is that we are more ready and free and bold in our witness to Christ. Or according to Ephesians 5, we are more ready, more free, more eager to overflow with psalms and hymns and spiritual songs and giving thanks to God.

Having the Holy Spirit marks one off as a Christian. You can’t be a Christian if you don’t have the Spirit. There are no Christians who don’t have the Holy Spirit. Being filled with the Holy Spirit is what all believers should seek to experience for the sake of the wonderful, Christ-exalting freedom and boldness and power that it brings.

“So, how do you know if you have the Holy Spirit?” he asks. And I’m responding, “You know you have the Spirit if you are, in fact, a Christian — if you have been born again.”