Reformed Baptista points to a great book amid Internet discussion and gives some helpful comments as well:
“[W]hile the famous Baptist John Bunyan allowed open communion, most of the signers of the 1689 did not. Was this due to hard-headed stubbornness, a reaction against the critiques by Presbyterians? Possibly, but how then does that reconcile with the words of the introduction to the 1689, which calls Presbyterian brethren? And deigns to show love in explaining their differences?
William Kiffin, one of the signers of the 1689, wrote “A Sober Discourse on the Right to Church-Communion” [Amazon], addressing the very reasons why he practiced “closed communion” (restricting the Lord’s Supper to only those professors who had been baptized by immersion). Why did he restrict the table? Because of Scripture:
OBJECTION #10: This is a dividing principle, and ’tis very censorious to judge none fit for communion in a Church, but such as are baptized thereby, unchristianing all other persons that are of another mind.
ANSWER: This is no other principle but what Scripture doth everywhere justify, as hath been largely proved before. And this objection rather chargeable on the contrary opinion, as being that which divides the ordinance from its proper use and by putting it out of its place, where God in his Word hath set it. There being no division by principle, but what is made by the ignorance of the persons that oppose it about the rule and order by which Christians ought to walk; or by their wilful neglect of that which is required by the Lord, of those that desire communion with the Church. For if the Lord of the family prescribe an order by which it should be governed, can it be reasonable that this rule should be broken for the sake of the servant’s ignorance or wilfulness? We censure none so rigidly as to take upon us to unchristian or unchurch them; all that we do (in discharge of our duty to God, and Faithfulness in our places) to labour to keep the Lord’s Ordinances in that purity and Order the Sacred Records testify they were left in, and in a spirit of Love and Meekness to contend earnestly for the Faith once delivered to the Saints; which we conceive to be a duty enjoined upon all Christians, &c.
Scripture is to regulate the Church’s practice. The elements of worship (which would include the ordinances of Baptism and the Lord’s Supper) are to be administered the way Scripture proscribes. If one sees that proper baptism is immersion according to the Scriptures, and that Christians who are baptized should be the ones to receive the Lord’s Supper (again, according to the Scriptures), then to allow those who are not baptized to the table (for sprinkling nor pouring is considered baptism) would be inconsistent with one’s view of Scripture. If you are not going to allow everyone to the table, then lines are to be drawn somewhere. This should be a reminder to always return to “WDSS?” or, “What Does Scripture Say”? Emotional pleas and intelligent rhetoric may be appealing, but if they are not rooted firmly and clearly in the Word then they must not be compelling.
There is no statement in the 1689 regarding whether baptized believers alone should take the Lord’s Supper. Since not all were in agreement on the issue, the Confession stated that “worthy receivers” partook of the elements, leaving the definition of worthy to individual churches. Obviously there is still disagreement today. However, if you respect Baptists despite disagreeing with them, then you should be able to respect those who decide to fence the table.