Understanding the Holy Eucharist, Our ‘Source and Summit’

Jimmy Akin

 Jimmy was born in Texas and grew up nominally Protestant, but at age 20 experienced a profound conversion to Christ. Planning on becoming a Protestant pastor or seminary professor, he started an intensive study of the Bible. But the more he immersed himself in Scripture the more he found to support the Catholic faith. Eventually, he entered the Catholic Church. His conversion story, “A Triumph and a Tragedy,” is published in Surprised by Truth. Besides being an author, Jimmy is the Senior Apologist at Catholic Answers, a contributing editor to Catholic Answers Magazine, and a weekly guest on “Catholic Answers Live.”

The Holy Eucharist was instituted by Jesus ‘on the night he was betrayed’ — which underscores the seriousness of receiving Communion while simultaneously betraying him.

Ercole de’ Roberti, “Institution of the Holy Eucharist,” ca. 1495
Ercole de’ Roberti, “Institution of the Holy Eucharist,” ca. 1495 (photo: Public Domain)

The Second Vatican Council describes the Eucharist as “the source and summit of the Christian life” (Lumen Gentium 11), but not everyone understands why.

Some are particularly perplexed as to why Holy Communion isn’t given to everyone and why the Church stresses the need to receive it worthily.

It thus can be helpful to review some of the basics about the Eucharist and its importance in Catholic life.

The Roots of the Eucharist

Anyone who attends Mass knows that the Eucharist was instituted by Jesus “on the night he was betrayed,” just before the Crucifixion. However, its roots go deeper in history.

The foundational event of Israel’s national life was the Exodus, when God took his people out of Egypt. At that time, God instituted the Passover meal, in which the Israelites sacrificed a lamb, painted their doorposts with its blood and consumed its flesh in a sacred meal (Exodus 12).

The blood on the doorposts caused God’s wrath to pass over the Israelites, and the flesh of the lamb strengthened them for their journey to the Promised Land.

On the way, God made a covenant with the Israelites. This covenant was instituted with sacrifices, and to signify the union of God and his people, Moses applied part of the blood to the altar and part to the people, describing it as “the blood of the covenant which the Lord has made with you” (Exodus 24:8).

But the Israelites were unfaithful, and God sent the prophet Jeremiah to announce a new and better covenant: “The days are coming, says the Lord, when I will make a new covenant with the house of Israel and the house of Judah,not like the covenant which I made with their fathers when I took them by the hand to bring them out of the land of Egypt, my covenant which they broke” (Jeremiah 31:31-32).

The Institution of the Eucharist

Jesus combined these themes when he instituted the Eucharist. The context in which he did so was a Passover supper. At the beginning of the meal, Jesus tells his disciples, “I have earnestly desired to eat this Passover with you before I suffer” (Luke 22:15). 

The Eucharist is thus the Christian equivalent of Passover. While the Passover meal pointed forward to the deliverance of the Israelites from Egypt, the Eucharist points forward to Christians’ deliverance from sin.

Christ himself takes the place of the Passover lamb. He is described as “the Lamb of God” (John 1:29), and Paul says that “Christ, our Paschal Lamb, has been sacrificed” (1 Corinthians 5:7).

During the Last Supper, Jesus took bread and said, “Take, eat; this is my body” (Matthew 26:26). The flesh of Christ as the new Passover lamb thus strengthens Christians for their journey to the heavenly Promised Land.

He also took a chalice and gave it to them to drink, saying, “this is my blood of the covenant, which is poured out for many for the forgiveness of sins” (Matthew 26:28). Like the original Passover lamb, Christ’s blood causes God’s wrath to pass over Christians because their sins are forgiven.

Just as the blood of the covenant instituted by Moses was applied both to the altar and the people, so is Christ’s blood. It is applied to the people when they drink from the chalice, and it is “poured out for many” on the altar of the Cross.

Jesus also is instituting the new and better covenant prophesied by Jeremiah. This is made particularly clear in Luke’s version, where Jesus says that the chalice signifies “the new covenant in my blood” (Luke 22:20).

The Eucharist thus sums up the themes God established with his people Israel and elevates them to a new level.

The original events involved the delivery of a single nation from slavery, the creation of a national covenant, and a journey to an earthly Promised Land. Now, with the coming of the Messiah, we have the deliverance of people from all nations from sin, the institution of a universal covenant, and the journey to the ultimate Promise Land — heaven.

The Eucharist in the Church

The Passover meal was not a one-time event but something God’s people did regularly to commemorate what he had done for them.

Similarly, Jesus did not mean the Eucharist to be celebrated just one time. He told the disciples, “Do this in remembrance of me” (Luke 22:19), and it became a regular feature of Christian life.

In fact, it was celebrated far more frequently than the Passover, which was held only once a year. In his letters to the Corinthians, St. Paul indicates that the Lord’s Supper was celebrated “when you meet together” (1 Corinthians 11:19) — something that occurred “on the first day of every week” (16:2). 

He wrote this around A.D. 53, so the Sunday Eucharist became a regular feature of Christian life very early.

Worthiness to Receive Communion

Just as the Israelites were unfaithful to the covenant established through Moses and could celebrate the Passover unworthily, Christians can be unfaithful to the New Covenant and profane the Eucharist.

After commenting on how Christ has been sacrificed as our Paschal Lamb, Paul immediately says, “Let us, therefore, celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth” (1 Corinthians 5:8).

He says the Eucharist is not to be received indiscriminately. Instead, an examination of conscience is needed. “Let a man examine himself, and so eat of the bread and drink of the cup” (11:28).

Receiving Communion unworthily can have dire consequences. Paul tells the Corinthians, “That is why many of you are weak and ill, and some have died” (11:30).

A sin he particularly warns against is idolatry, explaining that “what pagans sacrifice they offer to demons” (10:20). It was thus a mortal sin to partake both of pagan sacrifices and the Lord’s supper: “You cannot partake of the table of the Lord and the table of demons. Shall we provoke the Lord to jealousy? Are we stronger than he?” (10:21-22).

But idolatry is just one mortal sin. If a person commits any mortal sin and does not repent, he will not “inherit the kingdom of God” (6:9-10).

Jesus Himself

Why is it so important to receive Communion worthily? Why can failure to do so lead to dire consequences?

Jesus revealed the reason when he instituted the Eucharist: “This is my body … This is my blood.” 

Paul makes the same point: “The cup of blessing which we bless, is it not a participation in the blood of Christ? The bread which we break, is it not a participation in the body of Christ?” (1 Corinthians 10:16).

Consequently, “Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of profaning the body and blood of the Lord” (11:27), and “anyone who eats and drinks without discerning the body eats and drinks judgment upon himself” (11:29).

As these passages make clear, the Eucharist is Jesus himself. He is both the source of the Christian life and the summit toward which we are journeying. By contrast, mortal sin is a state in which one has rejected God. 

To receive Holy Communion in mortal sin is a contradiction. It is to embrace Jesus while simultaneously spurning him.