Baptism and the thief on the cross

An understandable weakness some Christians have (especially among the laity) is to rely on a one-shot prooftext for or against something. But this frequently leads to putting too much weight on a particular verse, and leaves them defenseless if their prooftext is challenged.

A case in point is using the thief on the cross to demonstrate that baptism is unnecessary for salvation. But that's rather anachronistic. Christian baptism doesn't really take off until after the Ascension. The situation of the thief on the cross is more like an OT Jew. At the very least, it's a transitional phase in redemptive history.

A better way to argue against the necessity of baptism is to point out that because baptism symbolizes certain facets of salvation, there are NT passages which sound like baptism is necessary for salvation, but that fails to take into consideration the nature of symbolism, where A stands for B. It confuses the illustration with the principle it illustrates. That's a deeper argument. 

Of course, that won't put an end to the argument. What I just said will be contested. But it's a stronger position to argue from, so that's where the argument should be engaged. 

I'd add that very few modern-day denominations or faith-traditions regard baptism as an absolute prerequisite for salvation. Nearly all of them make exceptions. 

It's become a fringe position, represented by the Churches of Christ and some KJV-onlyists.