John's baptism was not a Christian baptism even though it may have been transitionary in nature. That's all I'll say on this as I don't want the thread to totally depart from the OP.
Just as Abrahamic circumcision wasn't Mosaic? We'd have to start another thread on this.
This current thread is also suggestive concerning the question of baptism with (by) the Spirit into Christ which is symbolised by water baptism. I believe that some/many believers in both Reformed and other churches don't have as good a grip on Romans 6 and the meaning of their baptism as they ought. They understand fairly well the earlier chapters about being justified by faith alone, but Romans 6 is somewhat mysterious to them.
Therefore for some of them when they have a subsequent "experience" e.g. of assurance or whatever, if they are moving in charismatic circles, it gets labelled as "the baptism with the Holy Spirit."
To the extent that such a thing is a genuine work of God, they've probably come to a better understanding of what happened to them when they were regenerated i.e. of what happened to them when they were baptised with the Spirit by Christ into Himself, ingrafted into all He is and has done, including in particular His death, burial and resurrection.
Yet the Apostle views Romans 6 as basic teaching:
Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death?(Romans 6:3, ESV)
I think many - even Reformed believers - are well taught that justification is by faith alone in Christ alone through grace alone, but are less well genned-up on what it means that we have died and risen with Christ, and that in Him we have died to sin and to the law as a means of salvation.