Reading Acts 2 right now…. It just hit me, when Peter told the Jews he was preaching to to “repent and be baptized…” it was a radical statement. To a Jew, baptism meant something very specific.
To tell a Jew to be baptized was to tell him to take part in Mikveh. Mikveh was a ritualistic cleansing after taking part in an impure incident. Mikveh was also used for Gentile (non-Jew) Proselytes who wanted to become Jewish in order to identify themselves with the One True God – Yahweh.
So when Peter told the Jews on the day of Pentacost that they needed to REPENT and “Be mikvehed”, he was saying that they were impure, and not currently identifying with the one true God.