We Believe and We Obey!
Jesus' command to the Apostles is quite clear - they were to do what HE did at the celebration of the first Eucharist. Not only did He command that they "do this" but He decreed that bread, after He blessed it IS His body and wine, after He blessed it IS His blood. We, Catholics (and Orthodox) believe Him and obey Him! We do not come up with excuses and rationalizations for the words of our Lord here! He decreed it and we believe it! On the other hand, most non-Catholics will explain away the words of Jesus, claiming He was speaking figuratively.
This brings us back to what Jesus said, repeatedly, in John 6.
In John 6 Jesus declared, "Unless you eat My body and drink My blood, you have no life in you." This was not well received by those to whom He was speaking, in fact many of His "disciples" after hearing this "turned and walked with Him no more." Jesus didn't call them back and say, "Wait! I was only speaking figuratively, you don't REALLY have to eat My flesh and drink My blood!" No, He let them walk away, not in disbelief or lack of understanding - but PRECISELY because they DID understand Him and believed He was serious - and they could not abide by the teaching! THEN, He turns to the Twelve and does not explain it away to them either - but further challenges, "Will you also walk away?" At this, St. Peter answers, "To whom would we go? You have the words of eternal life."
The Eucharist Enables Us To Obey John 6!
It is through the Eucharist that we are able to fulfill the repeated commands we see in John 6. It is precisely because of John 6 that we don't rationalize or minimize the words of our Lord in Matthew 26:26 (or Mark 14:22 or Luke 22:19 or 1 Corinthians 11:24) - the Eucharist IS His body and IS His blood - just as He DECLARED IT!
Will YOU Also Turn And Walk Away?
You have a choice - accept the words of Jesus as He said them - or accept the rationalizations of men. The other option would be to do as His many disciples did in John 6, and "turn and walk with Him no more." If you accept the rationalizations of men, have you not already turned and walk with Him no more? It's time to stop listening to the lies of those who refuse to obey Jesus Christ - and come to Him in the Church He built, just as He promised He would do - and He didn't wait 1500+ years to build that Church!