The Lord’s Supper has long been a source of controversy and disagreement among believers. Some theological traditions believe that the bread and the wine in the celebration are transformed into the body and blood of Christ. Others teach that Christ is present in the elements but in a spiritual sense. Still, other churches hold that the Communion service is strictly a memorial designed to remind the believer of the Lord’s death for our sins.
In addition, there is a great diversity concerning how the Supper is conducted: passing plates or coming forward? One loaf or a tray of wafers? A common chalice or lots of little cups? Weekly or monthly or quarterly? Some of these matters are relatively unimportant, while others speak to how we understand the ordinance. With all these issues and so many divergent opinions floating around, it is no wonder many believers don’t seem to understand the Lord’s Supper very well.
Making the matter worse is that many churches neglect to explain Communion carefully and clearly as part of their celebration. The practice of “fencing the Table,” wherein the presiding minister would explain the meaning of the Table and make clear who was expected to participate, has largely gone by the wayside. In many of our churches, the elements are presented to the church with little more than a caution that only “born-again believers” are supposed to participate.
I don’t believe that we serve our congregations well by a lack of attention to the Lord’s Supper. In that light, let me give you two reasons why pastors should take the time to explain Communion clearly to their congregations as part of their celebration.
Many people don’t understand the significance of the Lord’s Supper
First, pastors need to explain the Lord’s Supper because many people don’t understand what is happening when the church comes to the Table. John Calvin wrote that Jesus gave us the Lord’s Supper celebration “to awaken, arouse, stimulate, and exercise the feeling of faith and love, and indeed, to correct the defect of both.”  It does this by focusing our attention on three horizons:
The Past – The Lord’s Supper is meant to help the church remember Jesus, particularly His body broken and His blood shed at the cross. For this reason, the apostle Paul wrote to the church at Corinth to instruct them about the Supper:
The Present – We often call this ordinance “Communion” because when God’s people come to the Table of the Lord, they are experiencing communion (or, we might say, “fellowship,” “friendship,” or “intimacy”) with the Lord and with one another. So the apostle Paul writes to the church at Corinth:
Paul understands the church’s celebration to be more than just a way of remembering what Jesus did in the past. It is also a way of experiencing something in the present moment.
Significantly, Jesus gave his followers a meal to celebrate their covenant relationship with him (cf. Exodus 12:8-11, Exodus 24:11), as a meal signifies friendship and acceptance. When we hear the invitation of the risen Lord Jesus to come to his table and respond in faith, we experience (in Paul’s words) “a participation” in his broken body and shed blood. Not only that, but we also share communion with our brothers and sisters at the Table. The “one bread” makes a diverse group into “one body.” The Lord’s Supper celebration allows God’s people to experience communion with the Lord Jesus and each other.
The future – The Lord’s Supper also focuses the church’s attention on the future return of Christ. The ordinance is temporary, designed for an age when we walk by faith and not by sight. There will be a day when the church will no longer need the visible reminders of Jesus’ love in the bread and the cup, for they will see Him face to face and will dine with him in the great marriage supper at the end of time (Revelation 19:9). When we take the bread and the cup, we stoke our longing for the return of Christ and the renewal of all things. For this reason, Paul wrote:
Most Christians do not understand the significance of the Lord’s Supper. As a result, they don’t anticipate it eagerly. They don’t prepare for it expectantly, and they don’t celebrate it joyfully. As pastors, we have the joyful duty of introducing our people to the delights of coming to the Lord’s Table.
They don’t understand who is supposed to participate
Second, pastors need to explain the Lord’s Supper because many people don’t understand who is supposed to participate. In recent decades, evangelicalism (particularly in America) has skewed heavily toward the individual. We rightly stress the need for believers to have personal faith, personal repentance, and personal obedience. And so, when it comes to the Communion celebration, it’s natural for us to think in terms of our personal feelings and self-evaluation.
But it is clear from Scripture that this ordinance has been given to the church, not merely to individual Christians. So, as we saw earlier in Paul’s words to the church at Corinth, the Lord’s Supper celebrates our vertical relationship with Jesus and our horizontal unity with one another in the body of Christ.
Not only that, but God tasks the Church with deciding who is and is not permitted to come to the Lord’s Table. Usually, the main prerequisite is baptism – once the Church admits someone into the New Covenant community through baptism, it also admits them to the church’s ongoing celebration of the New Covenant in the Lord’s Supper. Conversely, if someone claims to be a Christian, but their doctrine or way of life are contrary to the true gospel, the congregation is told not to allow that person to have Communion with the church (Matthew 18:17, Galatians 1:8-9, I Corinthians 5:9-11).
My point is not to address how your congregation or denomination understands church discipline, baptism, and the Lord’s Supper. Instead, I want to point out that God has tasked the church with proclaiming the true gospel and then instructing only those who have repented and believed in Jesus to come to the celebration of Communion. This means the Church should strongly discourage unconverted people from coming to the Table. But it should strongly urge genuine believers to participate. In any event, the Church should not leave it solely up to the individual to decide whether they are qualified to come to the Lord’s Table.
The Lord’s Supper is a wonderful gift to the church. But many people in the pews don’t understand its meaning well or who is supposed to participate in the celebration. For that reason, pastors should make sure to explain Communion carefully to the churches that they serve.
 John Calvin, The Institutes of the Christian Religion, 4.17.42