For those who require more evidence...
There is only one flock, one hope. All Christians should partake of the memorial.
John 6:28-56
So then they said to him, "What must we do to accomplish the deeds God requires?"Jesus replied, "This is the deed God requires-to believe in the one whom he sent." So they said to him, "Then what miraculous sign will you perform, so that we may see it and believe you? What will you do? Our ancestors ate the manna in the wilderness, just as it is written, 'He gave them bread from heaven to eat.'"
Then Jesus told them, "I tell you the solemn truth, it is not Moses who has given you the bread from heaven, but my Father is giving you the true bread from heaven. For the bread of God is the one who comes down from heaven and gives life to the world." So they said to him, "Sir, give us this bread all the time!"
Jesus said to them, "I am the bread of life. The one who comes to me will never go hungry, and the one who believes in me will never be thirsty. But I told you that you have seen me and still do not believe. Everyone whom the Father gives me will come to me, and the one who comes to me I will never send away. For I have come down from heaven not to do my own will but the will of the one who sent me. Now this is the will of the one who sent me-that I should not lose one person of every one he has given me, but raise them all up at the last day. For this is the will of my Father-for every one who looks on the Son and believes in him to have eternal life, and I will raise him up at the last day."
Then the Jews who were hostile to Jesus began complaining about him because he said, "I am the bread that came down from heaven," and they said, "Isn't this Jesus the son of Joseph, whose father and mother we know? How can he now say, 'I have come down from heaven'?" Jesus replied, "Do not complain about me to one another.No one can come to me unless the Father who sent me draws him, and I will raise him up at the last day. It is written in the prophets, 'And they shall all be taught by God.'Everyone who hears and learns from the Father comes to me. (Not that anyone has seen the Father except the one who is from God-he has seen the Father.) I tell you the solemn truth, the one who believes has eternal life.I am the bread of life. Your ancestors ate the manna in the wilderness, and they died. This is the bread that has come down from heaven, so that a person may eat from it and not die. I am the living bread that came down from heaven. If anyone eats from this bread he will live forever. The bread that I will give for the life of the world is my flesh."
Then the Jews who were hostile to Jesus began to argue with one another, "How can this man give us his flesh to eat?" Jesus said to them, "I tell you the solemn truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in yourselves. The one who eats my flesh and drinks my blood has eternal life, and I will raise him up on the last day. For my flesh is true food, and my blood is true drink. The one who eats my flesh and drinks my blood resides in me, and I in him. Just as the living Father sent me, and I live because of the Father, so the one who consumes me will live because of me. This is the bread that came down from heaven; it is not like the bread your ancestors ate, but then later died. The one who eats this bread will live forever."
John 10:16-17
"I am the good shepherd. I know my own and my own know me- just as the Father knows me and I know the Father-and I lay down my life for the sheep. I have other sheep that do not come from this sheepfold. I must bring them too, and they will listen to my voice, so that there will be one flock and one shepherd. This is why the Father loves me-because I lay down my life, so that I may take it back again. No one takes it away from me, but I lay it down of my own free will. I have the authority to lay it down, and I have the authority to take it back again. This commandment I received from my Father."
In addition to Atreyu's post.