I guess there might be some correlation between doubting your faith and becoming miserable.
I can see how this can be told as an example to those who still believe.
I used to think that someone with faith can never doubt, because something so true cannot be confused. I rejected the examples I was told, because once the Truth is found, it cannot be lost, and those who have lost their faith must have never really been faithful.
Honestly, I never feel more worthless than when I observe the similarity of humans to animals, when I think of intelligence as simply an added useful thing. And I have never felt more secure than when I saw humans and animals as completely different. When Heaven gave every reason to be alive, and Hell gave every reason to be good.
I prayed, not expecting an answer, but for the general good. I was the only animal in a room full of blessed beings, and I was envious. I felt expelled like the Devil.
Late at home, my eyes red from the lack of sleep. I do feel like the devil. But I am human and I am weak, and if you exist and if you have any mercy then I beg you to be merciful.