The Christian church is God’s community on earth. It was not born by human action but by the Lord Jesus sending the power of the Holy Spirit. Acts shows us the three great stages he used to do this (1:8). He comes first to Jewish believers (ch 2), then to half-Jews (ch 8) and, finally, to Gentiles (ch 10). Then, once the church’s birth is complete, it really begins to grow.
Our verses concern stage 1. Here Jesus forms his Jewish followers into God’s people, through a process called ‘baptism in the Spirit’ (1:5). John the Baptist and Jesus’ disciples dipped followers in water (Jo 4:1-2), as a sign of their turning from sin to be saved & brought into God’s kingdom; but the water only symbolised the real transformation which Jesus would perform by the Holy Spirit. Preparations for this event were laid out in chapter 1, followed by the believers waiting for God’s chosen day (1:4). This turns out to be Pentecost (v1), the Jewish festival which comes 50 days after Passover. The festival gives thanks for the first harvest crops and prays for the rest to come in. It is a suitable day for the Spirit to come because Jesus spoke of his people as being like a harvest (Lk 10:2) and so the 120 in Jerusalem are like the “first-fruits” of all he will gather.
The believers’ accommodation is suddenly immersed into the Holy Spirit (v2). This brings the sound of a powerful wind accompanied by the sight of tongues of fire touching each believer (v3). This terrifying scene echoes Israel’s rescue from Egypt. A fiery pillar of cloud lead them, opening a path through the Red Sea with a powerful wind (Ex 13:22; 14:19-22) – an event later associated with the Holy Spirit by the prophet Isaiah (Is 63:11-14). So these sights and sounds assure the believers that they are the renewed Israel, being lead by the Lord to a new world. But, in fact, they’re being given more than that. The ancient Israelites would never have dared touch or enter the holy cloud (cf Ex 19:16-25). Yet here it’s as though the cloud has come down safely upon the believers. They hear the storm-wind but it doesn’t blow them away! They are touched by the fire but it doesn’t burn them up (Lk 3:17)! So they know that Jesus’ death truly has cleansed them from sin, making them ready to receive the Holy Spirit: a blessing greater than Israel ever knew.
The followers of Christ, then, have been immersed in the Holy Spirit and, now, he will not leave them. They are the Spirit-empowered community of God. Any who join them will immediately experience this for themselves, as Peter later preaches (2:38). It’s vital to see that baptism in the Spirit is a one-off: verses 2 & 3 do not keep repeating through history; they describe a completed event. However, v4 does speak of something repeatable: filling with the Spirit. Now the Spirit is with us, Christians are to long and pray to know more of his power shaping us into the all that the community of God on earth ought to be (Ep 5:18; Ga 5:22-23). Does that include the miraculous speaking of other languages which v4 describes? No, that’s only given here as a sign to the Jews that they must turn to Jesus for salvation (2:40). Isaiah once said that when God uses foreign languages with Israel, it’s a judgement (Is 28:11; 1Co 14:). The Jews of Jerusalem are being called to take seriously what is happening and not simply write it off (v12,13). Nonetheless, though miraculous languages may have passed, the worldwide, multi-lingual church of Jesus Christ today is always to desire more of the Spirit whose coming brought about our birth.