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.
Obviously Christ wasn’t talking only about the Apostles at the Last Supper!
Not only Protestants, but even some of Christ’s disciples could not believe what Christ had just said! Christ did not just give a metaphor; He was totally explicit when He said “Except you **eat the flesh **of the Son of man, and drink His blood you will not have life in you”.
But Simon Peter and the other Apostles had true faith:
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.
I believe in Holy Communion (partaking of Christ’s Body, Blood, Soul and Divinity) because this is what the Catholic Church teaches. But I think the Church is doing just what Simon Peter did: accepting Christ at His word, for He is God.