Justin Martyr on the Real Presence:

"We call this food Eucharist, and no one else is permitted to partake of it, except one who believes our teaching to be true and who has been washed in the washing which is for the remission of sins and for regeneration [i.e., has received baptism] and is thereby living as Christ enjoined. For not as common bread nor common drink do we receive these, but since Jesus Christ our Savior was made incarnate by the word of God and had both flesh and blood for our salvation, so too, as we have been taught, the food which has been made into the Eucharist by the Eucharistic prayer set down by him, and by the change of which our blood and flesh is nurtured, is both the flesh and the blood of that incarnated Jesus" (First Apology 66 [A.D. 151]).

Another Early Church father describing the Real Presence of Jesus Christ in the Eucharist. It is comforting to know that the Catholic Church's interpretation of the Gospel of John regarding communion is in line with that of the early Church fathers, seeing as these men were taught by the Apostles, or people who the Apostles taught directly. The Early Church was indeed Catholic, reading the early Church fathers will vanquish all thought that it was protestant.

Pax Tecum