Danny, the context mentions water. The word "spirit" is not even used in the verse. The reason Peter brings up Noah is purely and simply because his audience will relate Noah to water, and water to baptism.
Baptism now saves you ... as an appeal to God for a clear conscience." It's the appeal that is doing the saving, not the baptismal ceremony.
What you're essentially doing is editing Scripture to conform to your POV. The verse says "baptism now saves you". Why is that such a problem? Of course it doesn't save because it is a physical washing of dirt from the body, but because it is, itself, "an appeal to God for a clear conscience". Don't say "it's the appeal that saves, not the baptism" ... the baptism is the appeal, the verse says that very clearly.
But based on how many scriptures leave it out, I don't beleive it is critical to the process.
Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world.
Sorry, but Jesus seemed to think it was pretty critical. I'll defer to his authority on the question. But remember what John the Baptist said, I baptize you with water, but the One that is coming will baptize you with the Holy Spirit. Paul does call the Baptism of John, the baptism of repentance.
Baptism is not the only form that appeals to the Father can take. And the thief is a prime illustration of that. I just posted a half dozen verses to you talking about salvation and they either don't mention baptism or it's performed after what the verses says is necessary for salvation.
Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world.
Jesus did command us to baptize and I don't dispute that. He also told us to observe all things whatsoever I have commanded you. Well He commanded a tremendous amount of things. Is it your contention that failure to do all that Jesus commanded voids salvation or that salvation is contingent or not conferred until after all things He commanded are done? Of course not, so why are you twisting this verse to make it something it's not. It's a command to baptize, but it doesn't make water baptism necessary for salvation. Jesus said many times that belief in Him was what was necessary for salvation and that all that believed in Him would have eternal life.
Water Baptism is important, but it is not critical to salvation. Only faith that generates an appeal is necessary.