What Is the Lord's Supper?

The 96th question of the Westminster Shorter Catechism asks, "What is the Lord’s supper?" It answers, "The Lord’s supper is a sacrament, wherein, by giving and receiving bread and wine according to Christ’s appointment, his death is showed forth; and the worthy receivers are, not after a corporal and carnal manner, but by faith, made partakers of his body and blood, with all his benefits, to their spiritual nourishment and growth in grace."

The Lord’s Supper is a sacrament. What is a sacrament? 

As the catechism had said earlier, “A sacrament is an holy ordinance instituted by Christ; wherein, by sensible signs, Christ, and the benefits of the new covenant, are represented, sealed, and applied to believers” (WSC 92, more on this question here).

What are the outward and sensible signs used in the Lord’s Supper? What do they represent? 

They are bread and wine. The bread is a sign of his body, which is for you. The wine in a cup is a sign of his blood, and of the new covenant in his blood, which was poured out for many for the forgiveness of sins (Matt. 26:26-29, 1 Cor. 11:23-25).

What is the significance of these elements being chosen to represent them? 

It is that his body is like bread, and his blood like wine, to give us spiritual nourishment and growth and eternal life (John 6).

What is to be done with these elements? 

They are to be given and received according to Christ’s appointment, set apart by prayers of thanksgiving and blessing and the words of institution. As the Larger Catechism explains, 

Christ hath appointed the ministers of his word, in the administration of this sacrament of the Lord’s supper, to set apart the bread and wine from common use, by the word of institution, thanksgiving, and prayer; to take and break the bread, and to give both the bread and the wine to the communicants: who are, by the same appointment, to take and eat the bread, and to drink the wine, in thankful remembrance that the body of Christ was broken and given, and his blood shed, for them. (WLC 169)

When and where should the Lord’s Supper be administered? 

It should be administered in the worship of the church. It is not a practice of private worship and it should not be administered to those not then present in the congregation. The church comes together to take the Lord’s Supper together as the body of Christ (Acts 20:7, 1 Cor. 11:18, 20, 33). Also, like baptism, it should be administered only by those ordained as ministers of the word, of which it is a seal.

How is the Lord’s Supper related to Christ’s death and sacrifice?

In it, Christ’s death is showed forth and remembered (1 Cor. 11:24-26), and a participation in the benefits of that once-for-all sacrifice on the cross is held forth and confirmed to believers (1 Cor. 10:16). But Christ’s sacrifice is not repeated or re-presented to God in the Lord's Supper. Christ alone offered himself as the sacrifice for sin, and he made and offered this sacrifice once for all time (Heb. 9-10). We do offer to God a sacrifice of praise and thanksgiving in the Lord's Supper, but not a sacrifice for sins.

Why is the Lord’s Supper called that? 

Because the Lord Jesus appointed this holy supper and is central to it (1 Cor. 11:20). Scripture also refers to “the cup of the Lord” and “the table of the Lord” (1 Cor. 10:21, 11:27). 

Why is it called Communion? 

Because it is a communion (participation, fellowship) in the blood and body of Christ (1 Cor. 10:16-17).

Why do some call it the Eucharist? 

This word is from the Greek word for “thanksgiving.” It came to be called the Thanksgiving since we give thanks in it, according to Christ’s example (1 Cor. 11:24).

Why is it called the breaking of bread? 

Because the bread is broken and distributed among the body of Christ (1 Cor. 11:24, 10:16). This is Luke’s term for it (Acts 2:42, 20:7).

Is the body and blood of Christ present in the Lord's Supper? 

Yes, the body and blood of Christ is truly held forth to believers in this sacrament. Christ does not give us empty signs, but truly offers what is symbolized by these signs, according to his words (Matt. 26:26-29). As Paul said in 1 Corinthians 10, the bread and cup are a participation in Christ’s body and blood.

How is the body and blood of Christ present and received in the Lord's Supper? 
Not by a transformation of the substance of the bread and wine into that of his body and blood, which is against both Scripture and reason and the nature of a sacrament. The Bible continues to call the elements bread and wine.

Not by inclosing his body and blood in the bread and wine, or by substantially uniting his body and blood with the bread and wine, which is the Lutheran view. His body remains a human body even when glorified, visible and finite. His body is in heaven. We do not partake of Christ "after a corporal and carnal manner." 

The body and blood of Christ are present sacramentally and spiritually. The bread and wine are signs and seals of his body and blood. What they represent is truly given to believers through the work of the Holy Spirit and by faith. His body and blood is offered to our faith, not our mouths and digestive system. Faith is how we feed upon Christ (John 6:35). His body and blood become life to us by the hidden work of the Holy Spirit, who makes us living members of Christ’s body and conveys to us all the benefits of his death (John 6:63, 1 Cor. 12:12-13). 

Those who partake of the visible elements in a worthy manner do inwardly by faith receive and feed upon Christ’s body and blood, with all his benefits, to their spiritual nourishment and growth in grace. The Spirit works through faith. As the French Confession says, “And thus all who bring a pure faith, like a vessel, to the sacred table of Christ, receive truly that of which it is a sign; for the body and the blood of Jesus Christ give food and drink to the soul, no less than bread and wine nourish the body.” The Larger Catechism carefully explains, 

As the body and blood of Christ are not corporally or carnally present in, with, or under the bread and wine in the Lord’s supper, and yet are spiritually present to the faith of the receiver, no less truly and really than the elements themselves are to their outward senses; so they that worthily communicate in the sacrament of the Lord’s supper, do therein feed upon the body and blood of Christ, not after a corporal and carnal, but in a spiritual manner; yet truly and really, while by faith they receive and apply unto themselves Christ crucified, and all the benefits of his death. (WLC 170)

What does it mean to partake of Christ’s body and blood? 

Think of how you partake of normal food. That sandwich does not benefit you when it remains apart from you. But when you eat it, you receive physical strength from it. Likewise, Christ’s body and blood does not benefit you when it remains apart from you. His sacrifice has been made, but it must be applied. You must “eat” his flesh and blood to receive life. That is, you must receive Christ’s body and blood by faith through the Spirit to have eternal life. Those who have union with Christ have communion in all the benefits of his death.

Are people unable to partake of Christ’s body and blood until they take the Lord’s Supper? 

No, Jesus calls everyone to partake of his flesh and blood by faith in response to the gospel, and to abide in him continually, like a branch in a vine. You ought to partake of him by faith before you come to the Lord’s Supper. But to confirm and strengthen this ongoing communion, Jesus also give us this sacrament.

What are the purposes of the Lord’s Supper?
As the Larger Catechism puts it, 

The Lord’s supper is a sacrament of the New Testament, wherein, by giving and receiving bread and wine according to the appointment of Jesus Christ, his death is showed forth; and they that worthily communicate feed upon his body and blood, to their spiritual nourishment and growth in grace; have their union and communion with him confirmed; testify and renew their thankfulness, and engagement to God, and their mutual love and fellowship each with other, as members of the same mystical body. (WLC 168)