At first, only heartfelt faith in Jesus Christ and repentance were required for baptism. Instruction in the new faith, more or less detailed and necessary for believers, took place afterward.
And so these believers who had been baptized constantly continued in the Apostles’ teaching. That is, for a certain time after baptism, they were instructed by the Apostles in the truths of the new faith and in the rules of the new life according to the Gospel teaching.
This, as well as the following expressions, does not mean that this whole mass of people was gathered, or used to gather, in one place or house. That would plainly have been inconvenient.
The believers probably gathered in various places and formed various groups or communities, in which the Apostles instructed them. They maintained constant communion among themselves and brought all believers of the different communities into that same communion.
Thus they were all like one large family, united by one spirit, though not constantly gathered together in one place.
This moral union of believers, this common brotherly relationship with one another, is designated by the narrator of Acts with the word “communion”: brotherly mutual love; compare 1 Pet 2:17 and 1 Pet 5:9.
According to this love, they had all things in common (v. 44).
“In the breaking of bread”: usually this expression means the eating of food (Lk 24:30 and similar passages). Yet it also has the higher meaning of partaking of the body and blood of Christ in the mystery of the Eucharist (1 Cor 10:16).
The Lord instituted the most holy mystery of the Eucharist after completing the Jewish Paschal supper; compare Lk 22:7–20 and parallels.
In the apostolic Church, especially in the earliest Church, believers celebrated the Eucharist in remembrance of Christ, according to His institution (Lk 22:19). Sometimes they did so even in the evening (Acts 20:7; Acts 20:11).
They also joined to this a meal called the supper of love, or the meal of love (Jude 1:12; 1 Cor 11:20–34).
To participate in this action of the Eucharist and in the meals of love is what it means to participate in the breaking of bread.
However, this expression undoubtedly also denotes the simple communion of believers with the Apostles at an ordinary meal. In ordinary human relations, participation in a common meal signifies brotherly mutual goodwill and spiritual communion among those participating.
The Lord Himself sanctified this by His example of participating in meals.
“And in prayers”: this does not mean prayers in the temple together with the people, which are discussed below (v. 46). It means special, private, communal prayers of a properly Christian character.
These prayers probably accompanied the celebration of the mystery of the Eucharist, as well as other communal gatherings in believers’ homes (v. 46), under the guidance of the Apostles.
From the conjunction of all these concepts, teaching, communion, breaking of bread, and prayers, by which the life of the first Christian community in Jerusalem is characterized here, we may conclude the following.
The subject here is the communion of believers in liturgical actions of a properly Christian character, that is, in liturgical gatherings. The composition of the divine service, this first Christian divine service, was teaching, the Eucharist together with the meal of love, and prayers.
Thus, according to this brief depiction, those who believed and were baptized on the day of Pentecost lived in the closest spiritual communion with the Apostles and with one another.
Besides constant private mutual relations, they often came together in communal liturgical gatherings under the guidance of the Apostles.
In these gatherings the Apostles instructed the believers, celebrated the mystery of the Eucharist, with the meals of love, and prayed with the believers.
Singing is not mentioned here. Yet since singing was customary in the Jewish temple and synagogue services, this custom undoubtedly passed into the liturgical gatherings of the earliest Christian Church.
In these gatherings was laid the beginning of divine worship properly Christian, separate from Jewish worship. Yet the Apostles and believers did not, for a time, break their connection with the Jewish temple worship; Acts 3:1 and following; compare the note on v. 46.