Kierkegaard

“Pain and suffering are always inevitable for a large intelligence and a deep heart. The really great men must, I think, have great sadness on earth.”
― Fyodor Dostoevsky, Crime and Punishment

“There is no good on earth; and sin is but a name. Come, devil; for to thee is this world given.”
― Nathaniel Hawthorne, Young Goodman Brown

“Man's nature, so to speak, is a perpetual factory of idols.”
― John Calvin

“For you will certainly carry out God's purpose, however you act, but it makes a difference to you whether you serve like Judas or like John.”
― C.S. Lewis, The Problem of Pain