Hi Perry,
"You cannot partcipate in your own salvation, it is a gift."
Fundementally, Jehovah's Witnesses believe this too -- that salvation is a free gift. They also believe in original sin.
"Man is utterly depraved and is infected with vanity."
You can believe that if you wish, but it is not the only view of humankind. The trap I see in this form of thinking is not much different than the "rotten old system of things" talk one hears at the Kingdom Hall. Although, there are many "improving world conditions" -- just think of how many childhood diseases have been reduced or removed in recent history -- saying such is not permitted within the Witness faith. It is not permitted, because it conflicts with a narrative about worsening world conditions and last days, etc. If man is not vain and depraved as you say, then what? Perhaps a story about an internal defect in need of a supernatural fix won't sound as correct.
Cheers,
-Randy