[quote="DaveBj, post:11, topic:312298"]
See patrick457's post #10. The mikvah could have been considered a sort of baptism. And the word "baptism" doesn't necessarily mean "Christian baptism;" for starters, John's baptism was not a Christian baptism.
I don't know. It just appeared in the Gospels, with John preaching repentance and then dipping repentant sinners in the waters of the Jordan River.
Josephus is apparently intrigued by John's baptism and understands it first as a purification of the body, playing the same role as the miqveh. The spiritual question involved is whether John has the power to forgive sins, perhaps with the aid of water that has mystical properties. Josephus strongly denies that John claimed any such power: the washing was an outward physical manifestation of a spiritual commitment to repentance and performing good works.
Now some of the Jews thought that the destruction of Herod's army came from God, and was a very just punishment for what he did against John called the baptist. For Herod had him killed, although he was a good man and had urged the Jews to exert themselves to virtue, both as to justice toward one another and reverence towards God, and having done so join together in washing. For immersion in water, it was clear to him, could not be used for the forgiveness of sins, but as a sanctification of the body, and only if the soul was already thoroughly purified by right actions.
Which is somewhat close to what the gospels say:
In those days John the Baptist came preaching in the wilderness of Judea, "Repent, for the kingdom of heaven is at hand." ...] Then Jerusalem and all Judea and all the region about the Jordan were going out to him, and they were baptized by him in the river Jordan, confessing their sins.
But when he saw many of the Pharisees and Sadducees coming to his baptism, he said to them, "You brood of vipers! Who warned you to flee from the wrath to come? Bear fruit in keeping with repentance. And do not presume to say to yourselves, 'We have Abraham as our father,' for I tell you, God is able from these stones to raise up children for Abraham. Even now the axe is laid to the root of the trees. Every tree therefore that does not bear good fruit is cut down and thrown into the fire."
The other differences between normal ritual baths and John's own is that while miqvaoth could be found almost everywhere, John holds his exclusively in different parts of the Jordan river (full of symbolic significance) and that while normal immersions are usually self-administered, in John's case you apparently needed him to perform.