Thought on baptism
Baptism is a ceremony or ritual where some individual pledges themselves to a larger religious group or movement. John saw it as a pledge to repentance, Peter saw it as a pledge to forgiveness, Paul sees it as a pledge to death. Wearing a cross, like wearing a skull and crossbones, was a declaration that one had passed out of the systems of the world and into the realm of death.
I'm wondering if there's something else at work as well. To me, early Christianity was the rejection of ritual and religion, the move from metaphysics to real-world engagement. So at this heart of ritual-rejection, we have an enacted ritual. Maybe this isn't as hypocritical as it seems.
Maybe baptism was the ritual to end all rituals, the cleansing from a system of impractical abstraction, and the rebirth as a being freed from religion. Maybe for one tied to ceremony, one needs a ceremony to allow one to leave. Maybe for Jews whose religious journey had begun with a cleansing, a cleansing was needed for the end of their religious journey.
John was baptizing into whatever was coming. Peter was baptizing into what had come. Paul was baptizing into a new identity. And maybe all of them were baptizing out of ritual and into life.