Browes -- I think this is the heart of your question, right?browes said:
Remember John the Baptist? He baptized in the OT "for the forgiveness of sins" -- or, more rightly, "because your sins are forgiven by God after you repent to Him."
So here is a proposition that the Jews would understand even though the words "in the name of Jesus Christ" were interjected. And, in fact, these words make a new claim --- that it is through Christ that forgiveness is given. It is not from God directly -- it is not awaiting some future event as the OT saints all their lives were. Peter is saying that for those who repent, the work of their forgiveness is "finished" and , along the lines of Rom 10:9-10, baptism (like "confess with they mouth) is an expression of your heart-acknowledged faith.
Of course, the imagery in baptism is a huge witness not only of the tie between OT and NT but of what actually happens to the believer when he/she repents -- death of self in repentance to God results in rebirth!
skypair