With Schopenhauer, the will to live is the root of sin; mortify this, deny the first instincts of your being, and you approach righteousness.

Buddhism has the same system.

And, in deducing all this from the plain teachings of Christianity, I am disposed to think you are right and consistent.
Christianity _is_ pessimism, so far as this world is concerned; we see that in such things as the thanksgiving for a' person's death in the burial service, and the prayer that the end of the world may soon come." He paused, and thought for a moment.
"But all this," he resumed, rising from his seat, and going to stand with one arm upon the mantelpiece, "is of course, with me, mere matter of speculation.

There are two allegories, which define Pessimism and Optimism.

First that of Adam and Christ.