Jungmann, Josef A., S.J. "Chapter Five: The Celebration of the Eucharist in the Writings of the Apologists." The Early Liturgy to the Time of Gregory the Great. (translated by Francis A. Brunner, C.S.S. R., Notre Dame, Indiana: University of Notre Dame Press, 1959, pp. 39-49.
Jungmann notes that among the early Christians the term "eucharist" is taken to indicate both the Sunday gathering and the sacrament itself. He asserts but does not document that "the action is called a sacrifice" (Jungmann 1959, 39). Justin's First Apology (ca. 150) describes a baptism, the Eucharist, and the whole of the Sunday service (ch. 65) (Jungmann 1959, 40). Jungmann particularly observes the threefold act of preparation. Fist there is a common prayer, participated in only by the faithful (Jungmann 1959, 41). Based on the record of prayer in the Didache one could easily conclude that this is the prayer we know as the Lord's Prayer. Second is the kiss of peace. Jungmann considers this to foreshadow the conciliatory nature of the Eucharist. The final element is the offering, which is brought to the one standing in front of the congregation, presumably the bishop. Bread, wine, and water are brought.
In Justin's First Apology chapter 67 there is a description of a Sunday service without a baptism. The Euchraistic prayer and communion are clearly present (Jungmann 1959, 42). By this time, at least in Justin's experience, the Sacrament was received every Sunday. Chapter 66 describes bread and wine as body and blood, and that the prayer of thanksgiving holds a performative force (Jungmann 1959, 43).
The entire service is pervaded with thanksgiving, as God has rescued his people out of the darkness of this world and into his light (Jungmann 1959, 44). ungmann illustrates the distinction between paganism and Christianity at some length.
The concept of sacrifice, though present as early as the Didache (ch. 14) was not emphasized in the second century (Jungmann 1959, 46). Jungmann suggests that sacrifice and thanksgiving may not have been understood as mutually exclusive. Even prayers can be seen as offering a gift to God (Jungmann 1959, 47). Jungmann grants that the thanks we give to God are not at all comparable to his gift to us. Yet they are what we can give. Jungmann also points out that Christian sacrifices are not blood offerings. They are spiritual in nature (Jungmann 1959, 48). Finally, our giving of thanks in the Eucharist is a memorial of Jesus' sacrifice for us. When we give thanks we are participating in his sacrifice.