NOTES for Act 2:42
Luke gives here a definition of the fullness of Christian life. Indeed, if the essence of this life is union with God, receiving His presence and action in each of our days, then where and in what has He left us this presence and action of His? You will say, everywhere? That is true, but this kind of presence of His is diffuse, impersonal; it does not imply personal relations with Him. Then you will say, in Jesus Christ? Yes, for He is with us "always, to the end of the age." He is the Word of God, come in the flesh, and He remains with us in the Word of God, in the Bible. Luke calls this "the apostles' teaching" because the apostolic perception of the Old Testament and the apostolic witness to Christ are precisely our Bible.
Where else do we meet Christ? Of course, in prayer. In prayer addressed to Him and in prayer to the Father, which we share with the Son. And there is a special presence of Christ in His Body and Blood, in the Eucharistic meal, the "breaking of bread." And finally, let us remember Jesus' words that "as you did it to one of the least of these My brothers, you did it to Me." That means there is His presence in every person we meet, and there is His special action in those who "received the Holy Spirit, having believed." Therefore "fellowship," brotherly love, and mutual help are also an encounter with Christ and a receiving of Him into one's life.
Let us pay attention to all these "channels of communication," not trying to emphasize some of them at the expense of others, and let us try to live not by "either-or" but by "both-and."