And while they were at supper, Jesus took bread and blessed and broke it and gave to his disciples and said: Take and eat. This is my body. And taking the cup, he gave thanks and gave it to them, saying: Take all of you and drink it. For this is my blood of the new covenant, which shall be shed for many for the remission of sins.The priest acts in persona Christi. Christ Himself, gives us his Body and Blood. We do not presume to take it, because we do not deserve it. It is a free gift from Our Lord.
He that eats my flesh and drinks my blood has everlasting life: and I will raise him up on the last day. For my flesh is real food and my blood is real drink. He that eats my flesh and drinks my blood lives in me: and I in him.
And behold I am with you always, even to the end of time.