I'm just trying to think through your argument Bruce. Baptists would argue that John the Baptist did bring in a change in redemptive history in the sense that the new covenant would be "repent and be baptized" and the new Testament would continue that theme. But the "you and your seed" provisions of the Abrahamic Covenant (in the paedobaptist view) are still in force. Feel free to expand on this. I am trying to piece the argument together.
And I'm trying to help you (and other readers) think for your own conclusion, putting together a valid argument by first spotting the disconnect between premise and conclusion in the original proposal. It could be that the conclusion is more valuable, and a better path to it found. Otherwise, it could be that the premise is sound, and a better conclusion should be reached.
Obviously, on this side we are not going to agree that the changes
announced by JtB (he did not
bring in the changes of NC redemptive history, which are the exclusive prerogatives of Christ) that they were encapsulated in the expression: "repent and be baptized."
We reply:
1) repentance was integral to the Old Covenant to any and all participants, failures notwithstanding; and would be a special prior consideration for a convert.
2) Baptism has the same basic function re. the covenant administration in the new era as circumcision did in earlier ages. "Repent and be circumcised" would be appropriate phrasing for a similar call under evangelistic settings from Abraham down to the day of Christ. The expression "repent and be baptized" is not phrased as an absolute order-of-events, any more than "baptism of repentance for remission of sins" is any order-of-events.
3) Baptism is not such a "new thing" that baptism (though by Hebrew designation) is unknown prior to the NT.
Therefore, to a paedobaptist practitioner, that which might seem to Baptist eyes to have some kind of inconsistency seems rather the opposite. JtB is saying things that aren't so radical that they should have little resonance with the church of his day.
When it comes to Pentecost, and we hear echoes of the Abrahamic promises in Peter's NT preaching (
I will be God to your children), we recognize in the NC the same kind of faith union as was essential to what came before, though not identical in expression.
What is my goal in showing this? It is not to decide for or against the Baptist conclusion, or the Baptist premise. Theoretically, either one of them could still be accurate. It is simply to show that what may look like good reasoning to him doesn't appear so to another POV, and he might even be persuaded that it isn't either from his own POV.