Who it is we receive in Communion

While they were eating, Jesus took bread, said the blessing, broke it, and giving it to His disciples said, “Take and eat; this is my body.” (Mt 26:26)
The above quote from the Gospel of Matthew relates the institution of the Eucharist at the Last Supper. Jesus said: “Take and eat: this is my body.” These are two distinct statements within one sentence.
The Church has sought to balance these two statements. “Take and eat” makes clear that Jesus wishes His gift of His Real Presence to be eaten. “This is my body” makes clear that it is truly the Real Presence of the Lord Himself.
The issue the Church has addressed through 2,000 years is this: The Lord meant us to eat the Eucharist, but, since it is the Real Presence of the Lord Himself, how can we sinners ever be worthy of receiving the Eucharist?
In the early Church, (The era of the Church referred to as the Age of the Fathers from 100 A.D. to about 800 AD), it was apparently the expectation that people were to receive the Eucharist as often as it was celebrated. There was also the practice of people being allowed to bring the Eucharist home in order to receive Communion even more often than Mass was celebrated. Although the early Church writers helped to develop a clear teaching that the Eucharist was the Real Presence of the Lord, the Eucharist was expected to be received and eaten.
As the Medieval Ages progressed (up to 1400 AD), the pastoral approach to Communion began to change. The focus was upon the awesome nature of the Eucharist, that it was sacred. People, due to a realization that we are unworthy to receive so great a gift, refrained from ever receiving Communion. Instead, Eucharistic devotions began to develop such as the first monstrances for adoration and benediction for worship. The Eucharist began to be adored rather than received. It is ironic that the same people who built the magnificent cathedrals of Europe tended not to receive Communion when they worshipped in these same buildings. Things had progressed to such an extent that an ecumenical council, the Fourth Lateran Council in 1215 AD, commanded, under the penalty of excommunication, that people must receive Communion at least once a year. The focus had moved from “Take and eat” to “This is my body.”
In keeping with the awesome privilege that it is the Lord Himself who we receive in Communion, the Church eventually imposed a strict fast to be observed before reception of Communion. Everyone was required to refrain from solids and liquids (even water and medicine) from midnight before receiving Communion. I recall reading about Blessed Francis X Seelos when he was deathly sick during the 1867 yellow fever epidemic. He and the other stricken priests would be awakened from their much needed sleep at midnight by the other priests in the house in order to receive Communion. Others were not so fortunate. A great sorrow for St. Elizabeth Ann Seton was that she could not receive Communion when she was seriously ill because she was in need of water and medicine before a priest could arrive to bring her Communion. 
This fast remained in effect until 1953 when Pope Pius XII broke with the tradition and allowed water and medicine before Communion. The fast has been amended further since then.
During the Second Vatican Ecumenical Council (1962-1965 A.D.), Pope Paul VI, looking back over the 2 millenniums of Church history, sought to bring some balance between “Take and eat” and “This is my body” by reducing the fast to the one hour before receiving Communion.” The developments since the Council have urged Catholics to restore the ancient practice of the Church of frequent reception of the Eucharist but with a clear understanding and belief that, even though we are unworthy of so priceless of a gift, the Lord calls us to receive His very self in the Eucharist unless we are in serious sin.
It is essential for us that, as we receive the Eucharist, we remember Who it is that we receive in Communion and rejoice that He calls us to His banquet.