One of the most remarkable transformations in history comes in the beginning of the second chapter of Acts. A group of obviously-still-confused men and women were gathered for prayer, and the Holy Spirit came like fire on them and set the world on its head. The epoch-making change in this group of people is shocking to consider. In Acts 1, only a few weeks earlier, these same disciples had been expecting the resurrected Jesus to restore the kingdom to Israel. This is truly marvelous: Jesus the Christ had risen from the dead, and all his teachings had still not sunk in. They still did not understand that what he was about was the restoration of all things, not only the restoration of Israel. This was why they needed the Holy Spirit: although they had been given explanation after explanation, some of them incredibly clear (as to the disciples on the road to Emmaus after Jesus’ resurrection from the dead). It did not matter: they still did not understand.

And then the Holy Spirit came, and as promised (see Acts 1:5 and cf. John 14ff.) the Spirit gave them understanding and wisdom like they could scarcely have imagined before. The external changes are notable in many ways: suddenly these disciples were speaking in languages they did not know and performing astonishing miracles. But the internal changes are what really tell us what happened. Peter and the others transformed from people dominated by fear to people characterized by bold confidence in the Lord—and not just any “lord”, but his Lord Jesus Christ. Likewise, whereas before they had still mistakenly been looking foran earthly rule, Peter and the others now recognized that Christ demanded allegiance no less when reigning beside his father in Heaven than he would have taking up a kingship here on earth. “Repent and believe,” they cry out to all, “and your sins will be forgiven and the Lord God will be your God.”

And each of us is filled with this self-same Holy Spirit, the means of the Son’s work for the Father in the Trinity. We have in us the same spirit that raised Jesus Christ from the dead, animated the early church, and has given life to his people ever since. This is not small thing. Indeed, though we tend in intellectual Reformed circles largely to overlook the work of the Spirit, and though our Charismatic brothers tend to emphasize points that Scripture does not, we need to invest more time in understanding the Spirit and his work rightly. But in any case, we have this glorious treasure: Christ formed in us by the very means of the salvation of the world, his Spirit.