Do not get drunk on wine, which leads to debauchery. Instead, be filled with the Spirit, speaking to one another with psalms, hymns, and songs from the Spirit. Sing and make music from your heart to the Lord, always giving thanks to God the Father for everything, in the name of our Lord Jesus Christ.
Ephesians 5:18-20 NIV
Being filled with the Spirit. This may mean different things to different people, depending on the tradition you come from. For some it might be a charismatic infilling that produced ecstatic utterances; speaking in tongues. For others, at the opposite end of the spectrum, it might be something that is kind of spooky and best to be avoided. But in the context of this passage, Paul tells us what he means by the term.
Singing
Many of us enjoy music. Listening to it. Or maybe singing along quietly. But that is the first way that Paul tells us to be filled with the Spirit. Erupt in song. And not just any song. Psalms, hymns, and spiritual songs. Songs that are praising God and extolling his name. Lift your voice in musical praise to God. Sing and make music in your hearts to the Lord.
And what is interesting about this is that Paul tells us to speak to each other in song. I suspect that rather than attempting to communicate via song, Paul is talking about singing together. Not just in the shower, or on a mountain top. But when we gather together. The only time my church generally sings together is when we gather for Sunday worship services. I think Paul is encouraging us to make music a bigger part of our life together.
Thanksgiving
The other aspect Paul talks about is thanksgiving to God. Thanksgiving for everything. Rejoicing in the Lord (Phil. 4:4) provides fertile soil for the Holy Spirit to work; filling you with his presence.
Be filled with the Spirit, lifting your voices in song together with the church. And be thankful in all things, whether good or bad.
