The First Apology is dated to between 155-157 CE, based on the reference to Felix as a recent prefect of Egypt
Early Church Practices[edit]
The First Apology provides one of the most detailed accounts of contemporary Christian practice. Those that are baptized are “brought by us where there is water,” where they are “born again in the same manner of rebirth by which we ourselves were born again.”[14] After the discussion of baptism, Justin describes the practice of the Eucharist, as well as the miracle of transubstantiation, in which “we have been taught that the food eucharistized through the word of prayer that is from Him, from which our blood and flesh are nourished by transformation, is the flesh and blood of Jesus who became incarnate.”[15] Finally, he provides information on the weekly Sunday meetings of the congregation, consisting of readings from the Jewish prophets and “the memoirs of the apostles”, prayers, and a meal.[16] (
en.wikipedia.org/wiki/First_Apology_of_Justin_Martyr)