The period of Christian antiquity covers the time of the New Testament, the centuries of the Christian underground during persecution, followed by the time of the early Doctors. What can we know about such times? We have the Bible. We can make assumptions based on what we read in the New Testament and in the many early Christian sources:
23. The Apostolic and post-apostolic periods are marked by a profound fusion of the cultic realities which are now called Liturgy and popular piety. For the earliest Christian communities, Christ alone (cf. Col 2,16) was the most important cultic reality, together with his life-giving word (cf. John 6,63), his commandment of reciprocal charity (cf. John, 13,34), and the ritual actions which he commanded in his memory (cf. 1 Cor 11,24-26). Everything else – days and months, seasons and years, feasts, new moons, food and drink… (cf. Gal 4,10; Col 2,16-19) – was of secondary importance.
The centrality of Christ, and of the basic early understanding of the Sacraments. Let’s recall that in addition to this Pauline tradition, we also have references in Acts to baptism, prayer, the Holy Spirit, and to the early worship which was heavily kerygmatic.
Early Christian devotion was brought from Jewish followers of Jesus:
Nevertheless, the signs of personal piety are already to be found among the first generation of Christians. Inspired by the Jewish tradition, they recommended following the example of incessant prayer of Jesus and St. Paul (cf. Luke 18,1; Rm 12,12; 1 Thes 5,17), and of beginning and ending all things with an act of thanksgiving (cf. 1 Cor 10,31; 1 Thes 2,13; Col 3,17). The pious Israelite began the day praising and giving thanks to God. In the same spirit, (giving) thanks for … actions during the day. Hence, every joyful or sorrowful occasion gave rise to an expression of praise, entreaty, or repentance.
When Paul advises his charges to pray at all times, was he just bringing his Pharisaical training into Christianity? Clearly, from the beginning, Paul and others were urging believers to a very high standard indeed. And Jesus, of course, suggested that our holiness needed to surpass the religious leadership of his day.
The Gospels and the writings of the New Testament contain invocations of Jesus, signs of christological devotion, which were repeated spontaneously by the faithful outside of the context of Liturgy. It must be recalled that it was a common usage of the faithful to use biblical phrases such as : “Jesus, Son of David, have mercy on me” ( ); “Lord if you wish, you can heal me” (…); “Jesus, remember me when you come into your kingdom” (…); “My Lord and my God” ( …); “Lord Jesus, receive my spirit” (..). Innumerable prayers to Christ have been developed by the faithful of every generation on the basis this piety.
I think Christians of many ages discover in the Scriptures expressions which give meaning to their piety. Additionally, God draws people through the Word to give expression and meaning to their regard and love for God.
The full document, the Directory on Popular Piety and the Liturgy, is online at the Vatican site.