Isn't it true that the Bible never says that baptism is for salvation, it's only a few obscure passages that are twisted to say that?

No.  The opposite is true. The concept of baptism for the remission of sins is all over the Bible. In fact, if you were to throw out all of the New Testament authors that teach baptism is for salvation than all you would be left with is James and Jude. And even James says that Faith isn’t enough by itself. (and Jude is only 25 verses long)  Here are just some of the scriptures. I encourage you to look them up and read them in context; see for yourself what the Bible says:

Mark 16:16
“He who has believed and has been baptized shall be saved; but he who has disbelieved shall be condemned.”

Acts 2:38
“Peter said to them, “Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit.”

Acts 22:16
“Now why do you delay? Get up and be baptized, and wash away your sins, calling on His name.”

Romans 6:4
“Therefore we have been buried with Him through baptism into death, so that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life.”

I Corinthians 12:13
“For by one Spirit we were all baptized into one body, whether Jews or Greeks, whether slaves or free, and we were all made to drink of one Spirit.”

Galatians 3:27
“For all of you who were baptized into Christ have clothed yourselves with Christ.”

Colossians 2:12
“...having been buried with Him in baptism, in which you were also raised up with Him through faith in the working of God, who raised Him from the dead.”

I Peter 3:21
“Corresponding to that, baptism now saves you—not the removal of dirt from the flesh, but an appeal to God for a good conscience—through the resurrection of Jesus Christ…”

Even without these passages there are enough others to conclude that baptism is an essential part of salvation, not to mention the Old Testament precedent and the practice of the early Church. But even if there were just one verse in the Bible that said that baptism is for salvation than we ought to sit up and take notice.

If baptism is not necessary or has another purpose, than where are the scriptures that say so? It is significant that the New Testament never tells of someone being baptized for anything other than the remission of sins.