In reference to the bottom right square in that presentation, and specifically in regard to the issue of water baptism, it seems to me that if a person approaches Paul’s epistles without importing a large theological framework beforehand, it is very difficult to conclude that water baptism is forbidden for members of the Body of Christ, as many Mid-Acts believers teach.
That does not mean that baptism is required. It certainly is not part of the gospel of grace, and Paul himself goes out of his way to distinguish the two. In I Corinthians 1:17 he says plainly, “Christ did not send me to baptize, but to preach the gospel.” That statement alone is enough to remove baptism from the category of saving ordinances. Salvation is through faith in Christ alone.
At the same time, that passage does not condemn the practice. In the very same context Paul acknowledges that he personally baptized Crispus, Gaius, and the household of Stephanas. His concern in that chapter is not that baptizing them was wrong, but that the Corinthians were dividing themselves into factions based on who baptized whom. In other words, Paul corrects their misuse of the practice without ever suggesting that the practice itself was sinful or illegitimate.
That observation matters because Paul is not shy about correcting things that should not be happening in the churches. When the Corinthians abused spiritual gifts, he corrected them. When they tolerated sexual immorality, he corrected them. When they distorted the Lord’s Supper, he corrected them. Yet nowhere in his epistles do we find an instruction telling believers to stop baptizing people.
Paul also speaks of baptism positively in several places. Romans 6 uses baptism imagery to describe union with Christ in His death and resurrection. Colossians 2 does the same thing. Whether one ultimately understands those passages to refer to Spirit baptism or not, the point remains that Paul employs the language constructively, not polemically.
For that reason it should not surprise us that many sincere believers read Paul and conclude that water baptism may still be practiced as a symbolic expression of faith, even if it is not required for salvation and not central to the gospel message.
From a Mid-Acts perspective we rightly insist that the gospel of the grace of God is faith in Christ apart from works, ordinances, or rituals. On that point there should be no compromise. Baptism does not save, does not cleanse sin, and does not add anything to the finished work of Christ.
However, recognizing that baptism is unnecessary for salvation does not automatically require the conclusion that the practice itself is forbidden.
A Mid-Acts believer could reasonably say something like this:
Paul clearly separates baptism from the gospel.
Paul personally baptized some believers.
Paul never commands believers to stop baptizing.
Paul occasionally uses baptism language positively in his teaching.
Given those facts, one could defensibly conclude that practicing water baptism as a voluntary symbol of identification with Christ is permissible, even if it is not required and carries no saving significance.
In other words, insisting that baptism is necessary would contradict Paul, but insisting that baptism is forbidden goes beyond what Paul actually says.
For those reasons, it seems to me that a Mid-Acts believer could reasonably hold that water baptism is unnecessary, non-saving, and secondary, yet still allowable as a symbolic act for those who wish to practice it.