Calvin and Acts

I'm just beginning to read the new English translation of Calvin's sermons on the first seven chapters of Acts translated by Rob Roy McGregor (and published recently by the Banner of Truth). These sermons have been available to us in the original French in the Supplimenta Calviniana for some time. I was fascinating by the sermon on Acts 2:41-42 to which the translator has given the title, "The Three Marks of the Church". His comment on the Lord's Supper reads: