Just finished Heart of Darkness. Spoilers!
Powerful novel. I am at a loss for words, truly. I desperately need to see Apocalypse Now.
Before I delve into any other points, I want to point out a surprising lack in comparisons of Kurtz to Jesus. To me, this stuck out most in my reading.
Yet Kurtz was more of a false messiah. He had great plans, great ideas, etc. but never could accomplish them. Instead he witnessed the "horror" of human nature.
And given Conrad's brutal outlook on human existence, I believe this is a clear refutation of religion and the existence of benevolent God. Maybe a criticism of Jesus himself. Both Kurtz and Jesus had loyal followers. Yet both left the world still in shambles.