Your attack on Calvin is ad hominem. While not attacking anyone living, it is nonetheless an effort to dispute Calvinism by attacking the person, rather than the substance of the argument.

As the Wikipedia says,

An ad hominem argument, also known as argumentum ad hominem (Latin: "argument to the man", "argument against the man") consists of replying to an argument or factual claim by attacking or appealing to a characteristic or belief of the person making the argument or claim, rather than by addressing the substance of the argument or producing evidence against the claim. The process of proving or disproving the claim is thereby subverted, and the argumentum ad hominem works to change the subject.

It is most commonly used to refer specifically to the ad hominem as abusive, sexist, racist, or argumentum ad personam, which consists of criticizing or attacking the person who proposed the argument (personal attack) in an attempt to discredit the argument.

Yeah, that's why I said that other verses can prove our point about baptism (I too have a very traditional view). Also, an argument can be made from the biblical function of baptism and the absence of anything else performing that function.

But, nonetheless, it is quite popular to argue that "Be baptized for the remissions of your sins" proves that not being baptized means your sins haven't been remitted.

Something I've often pointed out to people is that the recognition of my earlier point means we *have* to wrestle with John 3:5–which is a difficult and controversial text, as you pointed out.

Regarding John 3:5, I agree with your interpretation. (BTW, have you ever read Leon Morris' discussion of this text in the NICNT's commentary on John? It helpful.)

You are quite right. Negating "p implies q" does not produce "not p implies not q" (the converse). It produced "not q implies not p" — that is, in your example, if you've not been saved, then you've not been baptized.

The answer to your argument is found in John 3:5 —

(John 3:5) Jesus answered, "I tell you the truth, no one can enter the kingdom of God unless he is born of water and the Spirit."

As this actually says, "not p implies not q" (if you're not baptized, you're not saved) the verse is quite controversial.

I address the meaning at http://oneinjesus.info/2008/03/13/amazing-grace-b… and at greater length in my book Born of Water (http://oneinjesus.info/books-by-jay-guin/born-of-water/).

As you'll see, I exegete this verse quite traditionally. However, in Born of Water — and in this series — I suggest very different ways of looking at the question.

This site http://www.wayoflife.org/fbns/calvin-and-persecut…
has some good quotes showing that Calvin murdered Servetus and later said he'd like to do it all over again.

A quote they missed is this, where Calvin said: "He (Servetus) showed the dumb stupidity of a beast . . . He went on bellowing . . . in the Spanish
fashion: "Misericordias!" Misericordias, of course, is Spanish for mercy.

Calvin didn't believe in mercy for those who opposed his teachings; for them was only murder and hate. He actually said that his god is not unjust in that he "banishes all those human affections which soften our hearts; that he commands paternal love and all the benevolent feelings between brothers, relations, and friends to cease; in a word, that he almost deprives men of their nature in order that nothing may hinder their holy zeal." Sounds very Muslim, but its Calvin. "Why is so implacable a severity exacted but that we may know that God is defrauded of his honour, unless the piety that is due to him be preferred to all human duties, and that when his glory is to be asserted, humanity must be almost obliterated from our memories?" As if Servetus writing a book Calvin didn't like could really rob God of his honor. And even if it had, God commands "thou shalt not kill"! But Calvin continues "Many people have accused me of such ferocious cruelty that I would like to kill again the man I have destroyed. Not only am I indifferent to their comments, but I rejoice in the fact that they spit in my face.”

Calvin also wrote wrote to England's King Henry VIII recommending that the anabaptists be burned as an example to other Englishmen, in these words "It is far better that two or three be burned than thousands perish in
Hell." Oop! Calvin just denied his own doctrine of Fatalistic salvation. If the elect are fatalistically "once saved always saved" how could the anabaptists possibly cause them to fall? And if it is impossible for the non-elect to believe because Calvin's god has taken away their free will and decreed them to hell, then it would not be the anabaptists that would damn them, but Calvin's god! So, the killing of the anabaptists in no way would save anyone from hell according to Calvinism! Why then did Calvin command it? Because they were the true Christians and killing them would not keep people from going to hell but from going to heaven, because with them out of the way, Calvin could consign all men in the Satanic faith called Calvinism. So he though anyway–but he forgot about the REAL God.

Most of the verses that we use to prove baptism are in the following form: *If you are baptized, then your sins will be forgiven.*

In logic, such a statement is called a conditional.

I have often heard it stated that such statements *show* that if you aren't baptized, then your sins will not be forgiven. But that is a logical fallacy ("Denying the antecedent"; en.wikipedia.org/wiki/Denying_the_antecedent).

We need to be careful in arguing this way. Now, other verses and other considerations (the function of baptism and the absence of anything else doing that function) could prove the necessity/efficacy of baptism, but verses with the above-mentioned form cannot.