We do that when we partake of them as an unrepentant sinner. That is what it means to eat and drink of them unworthily.
1 Cor 10:[16] The cup of blessing which we bless, is it not a participation in the blood of Christ? The bread which we break, is it not a participation in the body of Christ?
What does Paul mean when he says that the bread and the wine are a participation IN the Body and Blood of Christ?
1 Cor 11:[27] Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of profaning the body and blood of the Lord.
& [29] For any one who eats and drinks without discerning the body eats and drinks judgment upon himself.
If it just a matter of bread and wine then why does Paul write here that those who receive them in an unworthy manner are guilty of blasphemy?
And if the sacrament of bread and wine has no real effect beyond being a symbol of profession to the community how can one partake of it unworthily much less be guilty of profaning the Lord?
John 6:[27] Do not labor for the food which perishes, but for the food which endures to eternal life, which the Son of man will give to you; for on him has God the Father set his seal."
John 6:55 “For my Flesh is true food, and my Blood is true drink.”
John 6:[54] “he who eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day.”
[56] He who eats my flesh and drinks my blood abides in me, and I in him.
What does Jesus mean when He says to “LABOR” for the food that leads to eternal life which He will give us?
What does Jesus mean when He says that His FLESH is true food and that whoever eats this food-eats His FLESH-will have eternal life?
Where in John 6 does the Lord say that he means to “spiritually eat His flesh”?
And where in John 6 does it say that His flesh-Jesus’ flesh- is of no avail?
I have another pair of scripture passages that points to transubstantiation:
John 2:
[1]On the third day there was a marriage at Cana in Galilee, and the mother of Jesus was there;
Now mind you this is the third day from the four days that preceded it; day 1 (Jn 1:1), day 2(the next day Jn 1:29), day 3( the next day Jn 1:35), day 4(the next day-Jn 1:43).
So this is the seventh day from the beginning. Whatever is going to happen on this day John is letting us know is very important.
[2] Jesus also was invited to the marriage, with his disciples.
We are at a marriage feast.
[3] When the wine failed, the mother of Jesus said to him, “They have no wine.”
[4] And Jesus said to her, “O woman, what have you to do with me? My hour has not yet come.”
[5] His mother said to the servants, “Do whatever he tells you.”
[6] Now six stone jars were standing there, for the Jewish rites of purification, each holding twenty or thirty gallons.
[7] Jesus said to them, “Fill the jars with water.” And they filled them up to the brim.
[8] He said to them, “Now draw some out, and take it to the steward of the feast.” So they took it.
[9] When the steward of the feast tasted the water now become wine, and did not know where it came from (though the servants who had drawn the water knew), the steward of the feast called the bridegroom
[10] and said to him, “Every man serves the good wine first; and when men have drunk freely, then the poor wine; but you have kept the good wine until now.”
[11] This, the first of his signs, Jesus did at Cana in Galilee, and manifested his glory; and his disciples believed in him.
What was it that Jesus did here at this wedding feast?
Did He not change water into wine?
Did he not change the substance of one thing into another?
Or is this also hyperbole?
