Judaism
Protestants insist that Jesus was just kidding at the Last Supper when He instituted the Holy Eucharist, that it was just a “parable,” that He just wanted us to be thankful for our food and say grace before meals. Really? Can you show me a parable that Jesus starts with “Amen, Amen, I say to you...”? “Listen up. I really mean this!”
Protestants should also research the many Eucharistic Miracles that have happened throughout the world for the last 2,000 years. Do an internet search. Many skeptical scientists have been confounded by such miracles.
Read John 6:35-70:
[35] And Jesus said to them: I am the bread of life: he that cometh to me shall not hunger: and he that believeth in me shall never thirst.
[36] But I said unto you, that you also have seen me, and you believe not. ...[41] The Jews therefore murmured at him, because he had said: I am the living bread which came down from heaven. [42] And they said: Is not this Jesus, the son of Joseph, whose father and mother we know? How then saith he, I came down from heaven? [43] Jesus therefore answered, and said to them: Murmur not among yourselves. ...[47] Amen, amen I say unto you: He that believeth in me, hath everlasting life. [48] I am the bread of life. [49] Your fathers did eat manna in the desert, and are dead. [50] This is the bread which cometh down from heaven; that if any man eat of it, he may not die.
[51] I am the living bread which came down from heaven. [52] If any man eat of this bread, he shall live for ever; and the bread that I will give, is my flesh, for the life of the world. [53] The Jews therefore strove among themselves, saying: How can this man give us his flesh to eat? [54] Then Jesus said to them: Amen, amen I say unto you: Except you eat the flesh of the Son of man, and drink his blood, you shall not have life in you. [55] He that eateth my flesh, and drinketh my blood, hath everlasting life: and I will raise him up in the last day.
[56] For my flesh is meat indeed: and my blood is drink indeed. [57] He that eateth my flesh, and drinketh my blood, abideth in me, and I in him. [58] As the living Father hath sent me, and I live by the Father; so he that eateth me, the same also shall live by me. [59] This is the bread that came down from heaven. Not as your fathers did eat manna, and are dead. He that eateth this bread, shall live for ever. [60] These things he said, teaching in the synagogue, in Capharnaum.
[61] Many therefore of his disciples, hearing it, said: This saying is hard, and who can hear it? [62] But Jesus, knowing in himself, that his disciples murmured at this, said to them: Doth this scandalize you? [63] If then you shall see the Son of man ascend up where he was before? [64] It is the spirit that quickeneth: the flesh profiteth nothing. The words that I have spoken to you, are spirit and life. [65] But there are some of you that believe not. For Jesus knew from the beginning, who they were that did not believe, and who he was, that would betray him.
[66] And he said: Therefore did I say to you, that no man can come to me, unless it be given him by my Father. [67] After this many of his disciples went back; and walked no more with him. [68] Then Jesus said to the twelve: Will you also go away? [69] And Simon Peter answered him: Lord, to whom shall we go? thou hast the words of eternal life. [70] And we have believed and have known, that thou art the Christ, the Son of God.
Read Luke 22:19-20:
[19] And taking bread, he gave thanks, and brake; and gave to them, saying: This is my body, which is given for you. Do this for a commemoration of me. [20] In like manner the chalice also, after he had supped, saying: This is the chalice, the new testament in my blood, which shall be shed for you.
Read 1 Corinthians 11:24-25:
And giving thanks, broke, and said: Take ye, and eat: this is my body, which shall be delivered for you: this do for the commemoration of me. [25] In like manner also the chalice, after he had supped, saying: This chalice is the new testament in my blood: this do ye, as often as you shall drink, for the commemoration of me.
See also The Real Presence of Christ in the Eucharist.
“Also, why do you not BREAK the bread/wafer as Jesus did? In fact, Catholics are so OCD about NOT breaking it, they claim it won't magically turn into Christ when it hits your stomach if it does break.”