Justin Taylor is hosting a conversation in response Mohler's post.
...baptism has been understood by all major branches of Christianity, throughout the centuries of Christian experience, to be a requirement for church membership and the fellowship of the Lord’s table. Thus, for Baptists to receive into the membership of a Baptist church (or to invite to the Lord’s Supper) any believer who lacks such baptism, is to receive non-baptized persons as if they were baptized.
Any compromise of Baptist conviction concerning the requirement of believer’s baptism by immersion amounts to a redefinition of Baptist identity. More importantly, it raises the most basic questions of ecclesiology. We must give those questions intent attention in these days. Otherwise, will there be any Baptists in the next generation?
For my part (and I'm definitely no Al Mohler or John Piper), the issue really boils down to three questions.
1. What is baptism?
2. What is the relationship between baptism (as defined in 1) and church membership?
3. What are the appropriate principles upon which to build a "novel" approach to question 2 (assuming one thinks the scripture is unclear on 1 and 2)?
Some of the discussants believe the Scriptures to be unclear or inconclusive on questions 1 and 2. But everywhere we see baptism on the pages of the NT the subjects are professing believers (not infants) by immersion. Even the great commission from our Lord, if we think the ordering of the words have any significance, makes baptism consequent to credible discipleship. "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit..." (Matt. 28:19). If we ask, "what is baptism?" we should arrive at a definition that rules out any rite that occurs before a person demonstrates a credible possession of saving faith in Jesus Christ.
Then the question becomes what relationship does such a view of baptism have with church membership. Certainly the way Paul assumes that the Christians in Rome were already baptized at least suggests that baptism was either a prerequisite for membership or normally conducted early in one's church membership experience (see Rom. 6:3). There doesn't seem to be any NT idea that one could be a member and not have been properly baptized as a repenting, professing believer in Jesus Christ.
But supposing one doesn't buy the brief argument above? On what principles would we form an alternative to the historical Baptist distinctives on this issue? It seems to me that much of this debate is fueled by a somewhat emotional "fairness" appeal. In other words, "since it would be unfair to exclude someone because they hold a different view of baptism, we should change our policy or reconceptualize the relationship between baptism and church membership." If I'm correct that a "fairness" principle is at work here, I'd suggest that it's an insufficient principle for driving the debate. As one who believes the scripture is sufficiently clear on questions 1 and 2 above, the critical principle it seems to me is "faithfulness," not fairness. We're called to be faithful even with the difficult truths of scripture, and we're called to submit to those truths in loving obedience to the Lord. After all, the next clause in the great commission passage reads, "...teaching them to observe all things that I have commanded you..." (Matt. 28:20).
Christians of genuine faith and strong conviction have historically disagreed over the matter of defining and practicing baptism. I appreciate the new proposals' effort at reaching visible unity across these disagreements, even though a visible unity alone is an insufficient grounds for driving this change. And I appreciate the way Christians are today discussing these issues with charity as well as conviction. I pray that the Lord would use these discussions to purify His bride.