The review posted by Lox includes conclusions about Darwin and his wife Emma that are not strictly true. His agnosticism was based on his observations, not to any great extent on his daughter's death. His wife's faith was not blinkered unquestioning belief.

In his autobiography, Darwin wrote in summary:
"Thus disbelief crept over me at a very slow rate, but was at last complete. The rate was so slow that I felt no distress [*and have never since doubted even for a single second that my conclusion was correct. I can indeed hardly see how anyone ought to wish Christianity to be true; for if so the plain language of the text seems to show that the men who did not believe, and this would include my Father, Brother and almost all my best friends, will be everlastingly punished.
And this is a damnable doctrine].

Mrs. Darwin annotated the passage in brackets... in her own handwriting. She writes: "I should dislike the passage in brackets to be published. It seems to me raw. Nothing can be said too severe upon the doctrine of everlasting punishment for disbelief- but very few now would call that 'Christianity,' (tho' the words are there.) There is the question of verbal inspiration comes in too. E. D." Oct. 1882.
The passage was not published.