From N.T. Wright’s new book, The Challenge of Acts:

When we put chapter 2 together, then, we find that the ancient promises about God filling the whole creation with his wisdom and glory have become focused on Jesus and his followers. The small sketch of the church in verse 42 functions eschatologically: Jesus’ followers become a small working model of the new creation. When the text speaks of great awe, of powerful signs (presumably healings) and of celebration and praising God, this is what’s going on: they are glimpsing the new creation itself, close up and personal. That remains the challenge for all Christian fellowships of whatever size or type. (p. 28)