Sadly, many catholics are poorly catechized or not at all. I've met adults who recall making First Communion but received no further instruction after that.
The next time some of your catholic friends make this comment, share these comments of the first christians with them.
What Did the First Christians Say?
Ignatius of Antioch, who had been a disciple of the apostle John and who wrote a letter to the Smyrnaeans about A.D. 110, said, referring to "those who hold heterodox opinions," that "they abstain from the Eucharist and from prayer, because they do not confess that the Eucharist is the flesh of our Savior Jesus Christ, flesh which suffered for our sins and which the Father, in his goodness, raised up again" (6:2, 7:1).
Forty years later, Justin Martyr, wrote, "Not as common bread or 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 nourished, . . . is both the flesh and the blood of that incarnated Jesus" (First Apology 66:1–20).
Origen, in a homily written about A.D. 244, attested to belief in the Real Presence. "I wish to admonish you with examples from your religion. You are accustomed to take part in the divine mysteries, so you know how, when you have received the Body of the Lord, you reverently exercise every care lest a particle of it fall and lest anything of the consecrated gift perish. You account yourselves guilty, and rightly do you so believe, if any of it be lost through negligence" (Homilies on Exodus 13:3).
Cyril of Jerusalem, in a catechetical lecture presented in the mid-300s, said, "Do not, therefore, regard the bread and wine as simply that, for they are, according to the Master’s declaration, the body and blood of Christ. Even though the senses suggest to you the other, let faith make you firm. Do not judge in this matter by taste, but be fully assured by faith, not doubting that you have been deemed worthy
of the body and blood of Christ" (Catechetical Discourses: Mystagogic 4:22:9).
In a fifth-century homily, Theodore of Mopsuestia seemed to be speaking to today’s Evangelicals and Fundamentalists: "When [Christ] gave the bread he did not say, ‘This is the symbol of my body,’ but, ‘This is my body.’ In the same way, when he gave the cup of his blood he did not say, ‘This is the symbol of my blood,’ but, ‘This is my blood,’ for he wanted us to look upon the [Eucharistic elements], after their reception of grace and the coming of the Holy Spirit, not according to their nature, but to receive them as they are, the body and blood of our Lord" (Catechetical Homilies 5:1).
Eucharist: From the Greek word, eucharistein (yoo kar is TAIN), "to give thanks": to the Heavenly Father for giving us the Divine Son, Jesus, for salvation and for the Eucharist Itself, in which we meet Jesus again.
Thank you so much for these quotes in order!