One theologian has said that the church is never as united as when it takes the Lord’s Supper together.
The Lord’s Supper is the commemoration of the once and for all sacrifice that Christ accomplished by which we were purchased from the wrath of God for the enjoyment of God. In the Supper we remember what Christ has done on our behalf and celebrate that He will return again. By faith, we commune with Christ, feeding spiritually on all that He is for us in the gospel.
But the Lord’s Supper is also more than that. Bobby Jamieson says that the Lord’s Supper “makes the many into one.” So when we take the Lord’s Supper we are seeing a visible line being drawn around the people of God. We are reaffirming our commitment to Christ and our commitment to one another. For most cases, those taking the Lord Supper will be members of the same local church (exception being for some visitors who are baptized members of other gospel preaching churches). By allowing someone to take the Lord’s Supper we are affirming them as citizens of the kingdom of heaven. Ordinarily, the Lord’s Supper is a privilege of membership in the local church. So to admit someone to the Lord’s Supper is to reaffirm their profession of faith as a congregation. The church has been authorized to give the Lord’s Supper as part of their exercise of the keys. The keys are used in the exercise of the sacraments.
Bare bones, church membership is to receive baptism and to regularly take the Lord’s Supper. This puts organic Christian life into the objective, authoritative structures ordained by God (so it is much more).
Is this at all practical?
One may be tempted to think that none of this really matters. But lets take a look at one area in which thinking clearly about the Lord’s Supper and church membership is important: evangelism.
Our evangelism is helped when a clear, bright line is drawn between the church in the world. When the name of Christ is not taken to mean anything in particular, people are inoculated to the true gospel. The glory of Christ is veiled by a counterfeit when people are allowed to “represent” Jesus when their lives show no supernatural change. God is shown to be glorious in His people’s enjoyment of His sufficiency. That sufficiency is shown in happy holiness. So it detracts from the fame of God’s name when those who claim to follow Christ make sin seem glorious and not God.
We try to protect the name of Christ by only accepting those into membership who we give a credible profession of faith. This protects the name of Christ by also protecting God’s people. The health of church members will be stunted by those who do not love Christ and who live lives of sin. Sin, even just a little, ruins the whole lump. Church discipline keeps the church’s witness pure. The church demonstrates their zeal for the glory of Christ and the heinousness of sin when we discipline those whom we can no longer affirm as representing Christ. Effectively, it removes Christ’s name from those who live lives contrary to the gospel. When we recommend someone stop taking the Lord’s Supper, we are saying that we can no longer affirm that the play for “team Jesus” any longer. Church discipline is, with broken hearts and tears in our eyes, taking the team jersey back.
The church is most effective when it is most obviously supernatural. In God’s economy, it is the compelling community displayed in the church that attracts sinners to God. The power of the gospel, promoted by gospel polity, shows the beauty of God. It shows people that they do not belong to the people of God. In that way, it becomes easier to explain the gospel.
The Lord’s Supper helps us to do that.