The Greek word used is an intense form which denotes a short outburst of spiritual power rather than a longterm endowment of the Spirit. This suggests that one can be filled with the Spirit on many occasions whilst still remaining full of the Spirit.1 This understanding is confirmed by the use of the same word elsewhere in Luke’s writings. Generally he uses this phrase when God's people are being empowered to speak (Luke 1:41, Luke 1:67; Acts 4:8, Acts 4:31; Acts 13:9) or with reference to a believer's devotion to God (Luke 1:15; Acts 6:3; Acts 13:52). Paul similarly commands all Christians to be filled with the Spirit (Ephesians 5:18; i.e., devoted to God), which happens as we let the word of Christ dwell in us (Colossians 3:16). In short, to be filled with the Spirit refers to the divine empowerment that enables God's people to carry out God's tasks.2 This includes obedience to his law (Ephesians 5:18–21; Ezekiel 36:27).
4 And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance.