You bring up an interesting point.Your opponent thinks he needs to save Christianity from Arminianism.
Okay; you think you need to save Christianity from Calvinism. You won't; its biblical roots run deep. I once thought that too. You know that I came to this forum to resume a five-year-old feud with a Calvinist (who shall remain nameless) from the old Key Life Forum? For all the passion and study I put into the issue, nobody changed their theological position because of me. Nobody changed their minds. Nobody's listening.
All I really need to do is be able to cogent present what I believe and why I believe it.
There's really been only two cases where I think somebody got hurt from believing in that theological system. I dislike that your opponent in the OP uses his perceived membership in the Elect to treat others like crap. That's not consistent with Christ's teachings. More serious is a brother on this forum (who's now permanently banned) who was a staunch Calvinist - but because he could not shake a certain besetting sin, he was convinced that he was not one of the Elect, and he could not trust Jesus to save him. THAT is a hill I'm willing to die on.
If it's God that does the choosing....how can we know He really chose us?
This is from The Institutes of the Christian Religion by John Calvin,
Book 3
Chapter 24
Paragraph 8
Besides this there is a special call which, for the most part, God bestows on believers only, when by the internal illumination of the Spirit he causes the word preached to take deep root in their hearts. Sometimes, however, he communicates it also to those whom he enlightens only for a time, and whom afterwards, in just punishment for their ingratitude, he abandons and smites with greater blindness.