That said, what's up with "whosoever"? It's like a universal translation in John 3:16, so all appeals to the Greek have to account for a somewhat-broad section of translation committees agreeing that the right translation of "hina pas ho pisteuwn" is "that whoever believes".
Let's start with the dictionary meaning of "whoever": "whatever person : no matter who -- used in any grammatical relation except that of a possessive". And that's fair enough, right? There's no reason to debate the fact that anyone who believes shall not perish but have eternal life. I believe that; any arminian would believe that. No questions asked.
"Well, hang on there you crypto-presbyterian pseudobaptist," says the man with the radio program in the back row, "You're a 'calvinist', right? It's your view that none of the non-elect are able to believe. In that respect, you do not mean 'whoever' – or 'whatever person'. You mean only the ones God has already chosen. This verse doesn't say, 'only the ones God has already chosen': it says 'all that believe' – or as the translation committees have translated, 'whoever believes'. Those are not the same thing."
Well, you're right in that this verse does not say specifically, "in order that all the ones God has elected from the foundation of the world." It says that the believers shall not perish. In fact, it says all the believers shall not perish. That's mighty strong talk if you ask me.
But mighty strong in what way? For the Arminian, what this verse also does not say is, "in order that all the ones who consider the options and choose based on free will shall not perish". To get there, you have to adopt a reading of the participle "pisteuwn" which changes the word from descriptive – that is, indicating a class based on a characteristic – to a word which is prescriptive. It also places a larger connotation on this word than is warranted by this verse, this passage, and frankly the theology of the book of John.
The strength of this passage is the scope of assurance it is offering. Jesus is discoursing with Nicodemus, and in speaking to this Pharisee he first gives an example of God delivering the Jews (and only the Jews) from the curse of the snake bite in the desert. But then Jesus says, in the same way when the Son of man is lifted up anyone (not just Jews) who believes in Him shall have eternal life.
The scope of salvation here is radically different than what Nicodemus is expecting, but it is also not the salvation of every person or even the atonement-in-potential for every person: it is the assurance that those whom Christ will save are saved in fact and saved without any doubt.
And those who are saved are the ones who believe – both Jews and Gentiles alike. One doesn't have to do grammatical contortions over the word "world" here to get that: one has to simply read the passage as it comes, in the manner which Jesus delivered it, and see the method of reasoning He was using with the Pharisee Nicodemus.
And now, before the data Nazis shut me down, the meta is open and you may take your wacks.