I am wearing a black shirt.
Do you believe me?
Does believing me burn more calories than not believing me?
If I am wearing a black shirt and you believe I am wearing a black shirt, does that somehow mean that you did some extra work that helped to make my shirt black?
No...but if you promised to give a million dollars to everyone who said they believed that you are wearing a black shirt, I say so, and you give me a million dollars (while denying millions to everyone who thinks your shirt is gray, or maybe that you're not wearing a shirt, or who have never heard of you or your shirt) then yes, I have performed a "work" that has "earned" me the million dollars based on the standards you set up ("Say you believe I'm wearing a black shirt, and I'll give you a million dollars!"). "Work" in the sense of Christian salvation doctrines is not about burning calories or physics. It doesn't take any more calories to wear clothes made of a single fiber than of blended fibers, but if you're a Torah-observant Christian of the sort that Paul was debating, you would call the former a "work" that demonstrates that you have real faith and/or is a necessary act to merit salvation. "Believe these six [or ten, or thirty-five, or however many] things and you go to heaven" is still a "work" in that sense. Do X, get Y. Quid pro quo. "I got the right answers on the Celestial Quiz! Yusss! Yay me!" *End-zone dance*
In order for the "salvation" to be truly
"unmerited" and unrelated to anything people do to earn it, it would either have to be arbitrary (Yahweh picks out some people to be saved and others to be damned before they're born, then insures that they're converted/not converted, respectively, without their having any say or influence in the matter) or universal (everybody goes to Heaven, even the atheists and pagans, and won't they be surprised!). Problem is, both kinda blow up the whole Christian salvation drama and "spiritual warfare" epic. The first turns it into a puppet show, the second sweeps away any perceived need to be involved with it at all because everyone gets to the finish line, whether they're in the race or not.
So, you're left with some version of "I believe the right things! That means I'm on Team Jesus, and I'm going to be one of the winners!" You can't say anything along those lines without the connotation that you've done the right thing, therefore you deserve to win. Another way to look at it: Imagine that you're standing before Jesus on Judgment Day. He's sent all the 'goats' on his left to Hell, then he turns to all the Christian believers on his right. "Actually, I've decided to pitch all of you guys into Hell too," he says, then reaches for the lever to the trap door under the white-robed crowd. If there's some part of you that thinks, "Hey, that's unfair!" or "Jesus would never do that, it would be unjust!" then, congratulations: you think you've earned
salvation somehow, and expect Jesus to honor that. If not, then you've got no basis to go around feeling confident that you're "saved" even if you do believe all the "right" things.
OT: I didn't really want to go to the trouble of joining that forum to debate on that thread, so Azdgari, if you like any of the arguments above, feel free to use 'em.