Chapter 65. Administration of the sacraments.
But we, after we have thus washed him who has been convinced and has assented to our teaching, bring him to the place where those who are called brethren are assembled, in order that we may offer hearty prayers in common for ourselves and for the baptized [illuminated] person, and for all others in every place, that we may be counted worthy, now that we have learned the truth, by our works also to be found good citizens and keepers of the commandments, so that we may be saved with an everlasting salvation. Having ended the prayers, we salute one another with a kiss. There is then brought to the president of the brethren bread and a cup of wine mixed with water; and he taking them, gives praise and glory to the Father of the universe, through the name of the Son and of the Holy Ghost, and offers thanks at considerable length for our being counted worthy to receive these things at His hands. And when he has concluded the prayers and thanksgivings, all the people present express their assent by saying Amen. This word Amen answers in the Hebrew language to genoito [so be it]. And when the president has given thanks, and all the people have expressed their assent, those who are called by us deacons give to each of those present to partake of the bread and wine mixed with water over which the thanksgiving was pronounced, and to those who are absent they carry away a portion.
Chapter 66. Of the Eucharist.
And this food is called among us eucharistia [the Eucharist], of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and who is so living as Christ has enjoined. For not as common bread and common drink do we receive these; but in like manner as Jesus Christ our Saviour, having been made flesh by the Word of God, had both flesh and blood for our salvation, so likewise have we been taught that the food which is blessed by the prayer of His word, and from which our blood and flesh by transmutation are nourished, is the flesh and blood of that Jesus who was made flesh. For the apostles, in the memoirs composed by them, which are called Gospels, have thus delivered unto us what was enjoined upon them; that Jesus took bread, and when He had given thanks, said, "This do in remembrance of Me, Luke 22:19 this is My body;" and that, after the same manner, having taken the cup and given thanks, He said, "This is My blood;" and gave it to them alone. Which the wicked devils have imitated in the mysteries of Mithras, commanding the same thing to be done. For, that bread and a cup of water are placed with certain incantations in the mystic rites of one who is being initiated, you either know or can learn.
Chapter 67. Weekly worship of the Christians.
And we afterwards continually remind each other of these things. And the wealthy among us help the needy; and we always keep together; and for all things wherewith we are supplied, we bless the Maker of all through His Son Jesus Christ, and through the Holy Ghost. And on the day called Sunday, all who live in cities or in the country gather together to one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, and, as we before said, when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, according to his ability, and the people assent, saying Amen; and there is a distribution to each, and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons. And they who are well to do, and willing, give what each thinks fit; and what is collected is deposited with the president, who succours the orphans and widows and those who, through sickness or any other cause, are in want, and those who are in bonds and the strangers sojourning among us, and in a word takes care of all who are in need. But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Saviour on the same day rose from the dead. For He was crucified on the day before that of Saturn (Saturday); and on the day after that of Saturn, which is the day of the Sun, having appeared to His apostles and disciples, He taught them these things, which we have submitted to you also for your consideration.
He also left us a clear foundation of mariology:
Chapter 100. In what sense Christ is [called] Jacob, and Israel, and Son of Man.
"Then what follows 'But You, the praise of Israel, inhabitest the holy place'declared that He is to do something worthy of praise and wonderment, being about to rise again from the dead on the third day after the crucifixion; and this He has obtained from the Father. For I have showed already that Christ is called both Jacob and Israel; and I have proved that it is not in the blessing of Joseph and Judah alone that what relates to Him was proclaimed mysteriously, but also in the Gospel it is written that He said: 'All things are delivered unto me by My Father;' and, 'No man knows the Father but the Son; nor the Son but the Father, and they to whom the Son will reveal Him.' Matthew 11:27 Accordingly He revealed to us all that we have perceived by His grace out of the Scriptures, so that we know Him to be the first-begotten of God, and to be before all creatures; likewise to be the Son of the patriarchs, since He assumed flesh by the Virgin of their family, and submitted to become a man without comeliness, dishonoured, and subject to suffering. Hence, also, among His words He said, when He was discoursing about His future sufferings: 'The Son of man must suffer many things, and be rejected by the Pharisees and Scribes, and be crucified, and on the third day rise again.' Matthew 16:21 He said then that He was the Son of man, either because of His birth by the Virgin, who was, as I said, of the family of David and Jacob, and Isaac, and Abraham; or because Adam was the father both of Himself and of those who have been first enumerated from whom Mary derives her descent. For we know that the fathers of women are the fathers likewise of those children whom their daughters bear. For [Christ] called one of His disciples previously known by the name of SimonPeter; since he recognised Him to be Christ the Son of God, by the revelation of His Father: and since we find it recorded in the memoirs of His apostles that He is the Son of God, and since we call Him the Son, we have understood that He proceeded before all creatures from the Father by His power and will (for He is addressed in the writings of the prophets in one way or another as Wisdom, and the Day, and the East, and a Sword, and a Stone, and a Rod, and Jacob, and Israel); and that He became man by the Virgin, in order that the disobedience which proceeded from the serpent might receive its destruction in the same manner in which it derived its origin. For Eve, who was a virgin and undefiled, having conceived the word of the serpent, brought forth disobedience and death. But the Virgin Mary received faith and joy, when the angel Gabriel announced the good tidings to her that the Spirit of the Lord would come upon her, and the power of the Highest would overshadow her: wherefore also the Holy Thing begotten of her is the Son of God; and she replied, 'Be it unto me according to your word.' " Luke 1:38 And by her has He been born, to whom we have proved so many Scriptures refer, and by whom God destroys both the serpent and those angels and men who are like him; but works deliverance from death to those who repent of their wickedness and believe upon Him.
Do not let anyone fool you. The Church of 2c was as Catholic as your Rosary beads.
His two "Apologies" and the "Dialogue with Trypho" are the only works of his still in existence.
Here is St. Justin's Second Apology.