Such elements include: Real Presence, the hierarchy of leadership (fathers, bishops, etc.), as well many elements common to most Christian denominations such as the de-Judization of Christianity.
I’d like to refer you to
scripturecatholic.com/the_eucharist.html . It has a very thorough scriptural explanation of the Eucharist and why Catholics believe in the Real Presence. You might never agree with us, but at least acknowledge that we do have a Biblical basis for it.
I will high light some of what I find to be helpful in the discussion of the real presence.
John 6:53 - 58 - Jesus does not correct their literal interpretation. Instead, Jesus eliminates any metaphorical interpretations by swearing an oath and being even more literal about eating His flesh. In fact, Jesus says four times we must eat His flesh and drink His blood. Catholics thus believe that Jesus makes present His body and blood in the sacrifice of the Mass. Protestants, if they are not going to become Catholic, can only argue that Jesus was somehow speaking symbolically.
John 6:23-53 - however, a symbolic interpretation is not plausible. Throughout these verses, the Greek text uses the word “phago” nine times. “Phago” literally means “to eat” or “physically consume.” Like the Protestants of our day, the disciples take issue with Jesus’ literal usage of “eat.” So Jesus does what?
John 6:54, 56, 57, 58 - He uses an even more literal verb, translated as “trogo,” which means to gnaw or chew or crunch. He increases the literalness and drives his message home. Jesus will literally give us His flesh and blood to eat. The word “trogo” is only used two other times in the New Testament (in Matt. 24:38 and John 13:18) and it always means to literally gnaw or chew meat. While “phago” might also have a spiritual application, “trogo” is never used metaphorically in Greek. So Protestants cannot find one verse in Scripture where “trogo” is used symbolically, and yet this must be their argument if they are going to deny the Catholic understanding of Jesus’ words. Moreover, the Jews already knew Jesus was speaking literally even before Jesus used the word “trogo” when they said “How can this man give us His flesh to eat?” (John 6:52).
John 6:55 - to clarify further, Jesus says “For My Flesh is food indeed, and My Blood is drink indeed.” This phrase can only be understood as being responsive to those who do not believe that Jesus’ flesh is food indeed, and His blood is drink indeed. Further, Jesus uses the word which is translated as “sarx.” “Sarx” means flesh (not “soma” which means body). See, for example, John 1:13,14; 3:6; 8:15; 17:2; Matt. 16:17; 19:5; 24:22; 26:41; Mark 10:8; 13:20; 14:38; and Luke 3:6; 24:39 which provides other examples in Scripture where “sarx” means flesh. It is always literal.
John 6:55 - further, the phrases “real” food and “real” drink use the word “alethes.” “Alethes” means “really” or “truly,” and would only be used if there were doubts concerning the reality of Jesus’ flesh and blood as being food and drink. Thus, Jesus is emphasizing the miracle of His body and blood being actual food and drink.
Now, my favorite from St. Paul is 1 Cor. 11
23 For I received from the Lord what I also handed on to you, that the Lord Jesus, on the night he was handed over, took bread,
24
and, after he had given thanks, broke it and said, “This is my body that is for you. Do this in remembrance of me.”
25
In the same way also the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.”
26
For as often as you eat this bread and drink the cup, you proclaim the death of the Lord until he comes.
27
Therefore whoever eats the bread or drinks the cup of the Lord unworthily will have to answer for the body and blood of the Lord.
28
A person should examine himself, and so eat the bread and drink the cup.
29
For anyone who eats and drinks without discerning the body, eats and drinks judgment on himself.
30
That is why many among you are ill and infirm, and a considerable number are dying.
