Thanks jgnat,
I didn't mean to introduce baptism as "another topic," just to express that, imo, comparing the WT treatment of baptism and the Eucharist reveals a major inconsistency. Those two "sacraments" or "rituals," both implying a symbolical yet concrete physical gesture (getting immersed in water, eating bread and drinking wine) in a religious setting were common to most if not all early Christian communities -- even though their interpretation was not. Still the Society manages to apply one to both its "classes" and the second to just one of them. Go figure.
The question might be better worded as, on what scriptural grounds does the WT require Christian baptism from people who are not meant to become part of the "Christian congregation" in the strict WT sense of that expression?
Of course from a sociological perspective the why is crystal-clear: baptism is regarded as a commitment, and it gives the organisation power over the lives of people.
In summary, then, the descriptions of baptism in Romans 6 and 1 Corinthians 15:29 indicate that it involves water, and all Christians participate as members of the same body?
1 Corinthians 15:29 (baptism for the dead) is not relevant as it obviously describes a local custom, so far unattested anywhere else afaik. And even in its farfetched WT translation/interpretation it would give no hint as to the form of baptism. The Insight book uses only Romans 6 to show that the verb baptizein originally carries the idea of immersion, which is basically right -- although the exact reasoning is flawed, inasmuch as baptizomai eis Khriston may equally be construed as an elliptical form of baptizomai eis to onoma Khristou, "to be baptised in the name of Christ", where eis loses its "local" sense of "into". Anyway, the argument would be utterly pointless if Paul, in that passage, was not giving his interpretation of water baptism (= immersion) as symbolic of union with Christ's death and burial, introducing to the "new life" of the resurrected Christ.
As a side note, I find it fascinating that one of the verses, in the original greek, speaks of a different purpose for baptism that the fundamentalist bible scholars ignore. It's a danger, isn't it, to try and harmonize the scriptures where there isn't any?
Perhaps not a different purpose for baptism in general but a particular Corinthian ritual in addition to the common Christian practice of baptism as introduction into the Church (aka Christ's body). I would add that the vast majority of conservative scholars do acknowledge that this text means just what it says, vicarious baptism on behalf of dead people.
Btw, a more problematic issue in this verse, from the Protestant standpoint, is that Paul justifies the practice of "baptism for the dead" by exactly the same reasoning about resurrection which is used to justify prayer and sacrifices "for the dead" in 2 Maccabees 12:43f. Just compare:
He (Judas) also took up a collection, man by man, to the amount of two thousand drachmas of silver, and sent it to Jerusalem to provide for a sin offering. In doing this he acted very well and honorably, taking account of the resurrection. For if he were not expecting that those who had fallen would rise again, it would have been superfluous and foolish to pray for the dead (huper nekrôn).
Otherwise, what will those people do who receive baptism on behalf of the dead (huper tôn nekrôn)? If the dead are not raised at all, why are people baptized on their behalf (huper autôn)?
