I recently had an exchange with an intemperate freewill theist:
"Calvinism tells sinners there is nothing they can do to change their eternal fate."
That confuses predestination with fatalism. Sure, there's nothing you can do to change a predestined outcome, but that hardly means faith or lack of faith is irrelevant to the outcome–for what sinners do or don't do is, itself, a predestined factor leading to the predestined outcome. The outcome won't happen apart from intervening causes.
"Calvinists are dangerous heretics because they insist that God has NOT made a SINCERE offer of salvation to the whole world through the sacrifice of Jesus Christ, His only son."
The offer of salvation is a conditional offer: if you repent of your sins and put your faith in Jesus, you will be saved. That's a sincere offer that's entirely consistent with Calvinism.
"God saves ONLY a relative handful that He Himself has chosen to save, and that these lucky few cannot"
That's a willfully ignorant Arminian trope. Calvinism is neutral on what percentage of humanity will be saved. Some Calvinists think it will be the majority.
"Is this something I can choose to do, or do I have to hope and pray that my 'dead spirit' has been supernaturally "regenerated" first?"
Unless you're Pelagian, even evangelical freewill theists believe prevenient grace is necessary to enable sinners to repent and believe the Gospel.
What makes an offer a bona fide offer is that if anybody complies with the terms of the offer, he will get what he was offered.
To take a comparison, suppose a butcher offers to sell two pounds of chopped liver for the price of one. If you only buy one pound, you don't get half price. You have to buy two pounds.
Okay, but suppose I can't stand the taste of liver. In that sense, I can't take him up on the offer.
Does my distaste for chopped liver make the offer insincere? Not by any reasonable definition of a bona fide offer.
Once again, are you ignorant of evangelical freewill theism? According to evangelical theology generally, original sin renders humans unable to accept the Gospel unless God provides necessary preliminary grace. In Arminian theology, that's prevenient grace. To deny that is Pelagian.
In addition, you keep missing the point. The stated purpose of the chopped liver analogy is to illustrate that an offer isn't rendered insincere due to the inability of a customer to be receptive to the offer. A sale on chopped liver is a bona fide offer even if many customers hate chopped liver.
"So the offer--at whatever price--is INSINCERE if the person it is being offered to has no ABILITY to receive it."
People who can't stand chopped liver are unable to enjoy the taste of chopped liver. Therefore, they are constitutionally unreceptive to the offer. They find the offer repellant.
It is insincere for the butcher to offer chopped liver unless every customer is able to enjoy the taste of chopped liver?
No. It's only insincere in case the butcher has no intention to giving them what was offered if they comply with the terms of the offer.
Moreover, the butcher isn't even offering chopped liver to customers face-to-face. He simply put an ad in the newspaper.
Actually, the reprobate don't show up. That's the point. It's not as if they show up, only to be served bad food. Rather, they refuse to come because they hate the food.
Or, to use my analogy, it's not as if they go to the store to buy the chopped liver, present their coupon, only to be charged full price. No, they don't take the butcher up on the offer in the first place since they hate chopped liver.
But there are other customers who just love chopped liver. They go to the store, present the coupon, and get two for the price of one–exactly as advertised. A bona fide offer.
Dropping the metaphors, the elect accept the Gospel and the reprobate reject the Gospel.