Over the past month or so I've been giving some thought to the issue of open and closed communion. When I was young I attended an Independent Fundamental Baptist Church which practiced closed communion, but since that time, I've met very few Evangelicals, aside from the Plymouth Brethren, who would subscribe to that view. Since most of us who have grown up in baptistic denominations have probably always taken open communion for granted without thinking about it too deeply, I want to present several arguments in favour of closed communion.
Before I present the case, let me define the terms. Advocates of open communion believe that the Lord's Supper is open to everyone who has professed personal faith in Jesus Christ alone for salvation. In a Baptist context, advocates of closed communion seek to restrict the Lord's Supper to believers who have been baptized by immersion. Some advocates of closed communion will go even further and restrict communion to members of a particular local congregation. Although I've never been overly dogmatic on this issue, I personally think that the Lord's Supper should be restricted to believers who have been baptized by immersion. The arguments which support this view are as follow:
1) Water Baptism precedes the Lord's Supper in the apostolic pattern
The strongest argument in favour of closed communion is found in Acts 2, although I would be quick to concede that we ought to use great caution in deriving normative patterns or doctrine from narrative portions of Scripture. Nevertheless, the order of events in Acts 2 does seem to lend considerable support to the practice of closed communion, viz. Repentance (v. 38) --> Water Baptism (v. 38) --> Church Membership (v. 41) -->Lord's Supper (v. 42).
Furthermore, there is not a single example in Scripture of a believer who is admitted to the Lord's Supper before being properly baptized. Once again, I will admit that this is an argument from silence, but it is still quite striking that nobody appears to partake of the Lord's Supper until they exercise faith and are baptized. (ie. Ethiopian Eunuch - Acts 8:36-38; Saul/Paul - Acts 9:18; Cornelius - Acts 10:44-47; Lydia - Acts 16:14-15; Philippian Jailor - 16:30-33)
2) Water Baptism precedes the Lord's Supper in the order of their institution
This is far less compelling, but interesting to think about nevertheless. Jesus instituted Water Baptism at the beginning of His earthly ministry and the Lord's Supper on the same night that He was betrayed.
3) Water Baptism precedes the Lord's Supper in their doctrinal order
Among other things, Baptists believe that Water Baptism is symbolic of a believer's death, burial and resurrection with Christ. Baptism is the outward sign of the inward work of regeneration effected by the Holy Spirit. Whereas circumcision was the sign of the Abrahamic Covenant and sealed upon the hearts of the Jewish people the tremendous promises that God had made to Abraham (cf. Gen 12:1-3), Water Baptism is the sign of the New Covenant in Christ, which seals upon the heart of the Christian the promises that God has made to us who have placed our faith in Jesus alone for salvation. Baptism has no saving power, but it is a non-negotiable part of the process of becoming a disciple of Christ (cf. Matt 28:18-20). The modern notion that a person can be saved and not worry about water baptism is utterly foreign to Biblical Christianity.
The Lord's Supper, unlike Baptism is an ongoing ordinance. Baptism is the initiatory ordinance which symbolizes new birth, whereas the Lord's Supper serves as an ongoing reminder of the broken body and shed blood of our Lord, so that our faith can be continually strengthened and nourished "as often as we eat the bread and drink the cup".
The main point is this - just as a baby must be born before she can eat and be nourished, so the ordinance symbolizing new spiritual life doctrinally precedes the ordinance symbolizing ongoing nourishment and sustainance. To reverse this order is to confuse the doctrinal significance of these two ordinances.
4) No other orthodox Christian denomination permits non-baptized believers to partake of the Lord's Supper
Although an appeal to tradition doesn't necessarily prove or disprove anything, Baptists who practice open communion ought to at least be aware of the novelty of their practice. Every other Christian denomination that I am aware of recognizes that Baptism ought to precede the Lord's Supper.
5) Historically, Baptists been strong advocates of Closed Communion.
The Puritan forerunners of the Baptists were strong advocates of closed communion by and large. Before being admitted to the Lord's Table, a person was required to give an account of their conversion to the elders of the church. This had two primary advantages: 1) It helped to protect the purity of the visible church - something which is still a great concern for Baptists; 2) It enabled the church to exercise discipline. In the Reformed Tradition, believers under church discipline were typically barred from the Lord's Table - a practice which has almost completely disappeared today with the advent of open communion. During the early 18th century, some Puritans such as Solomon Stoddard began to practice open communion. This practice was strongly opposed by Stoddard's own grandson Jonathan Edwards - a doctrinal stand which ultimately cost him his pastorate!
Like Edwards and the Puritans, the earliest English Baptists practiced and defended closed communion because the majority of them believed, as I've argued above, that Baptism is a pre-requisite for the Lord's Supper. Some editions of the First London Confession of Faith (1644) explicity endorse the practice of closed communion: Article XXXIX - "That Baptism is an Ordinance of the New Testament, given by Christ, to be dispensed only upon persons professing faith, or that are Disciples, or taught, who upon a profession of faith, ought to be baptized and after to partake of the Lord's Supper."
Interestingly, the Second London Confession (1689) does not contain this stipulation and probably reflects a diversity of opinion among Baptists on the issue. Shortly before the publication of this Second Confession, William Kiffin (the most important Baptist theologian of the 17th c.) and John Bunyan (author of the Pilgrim's Progress) had a lively debate about this subject in print with Kiffin defending closed communion, and Bunyan defending open communion.
Other notable Baptists who have defended closed communion include Benjamin Keach, John Gill, A.H. Strong, T.T. Shields and Mark Dever. One of my Baptist heroes who defended open communion was Charles Haddon Spurgeon!