"Because I'm a Karamazov. Because when I fall into the abyss, I go straight into it, head down and heels up, and I'm even pleased that I'm falling in just such a humiliating position, and for me I find it beautiful." (3.3.29)
At this early point in the novel, Dmitri can only appreciate his "humiliations" in a sensuous or artistic way – whatever a muddled person like Dmitri means by "beautiful." But much later in the novel, this appreciation for the beauty in his suffering will open the way for his acceptance of suffering as a path to redemption.
Alyosha realized at the first sight of [Katerina], at the first words, that the whole tragedy of her situation with respect to the man she loved so much was no secret to her, that she, perhaps, knew everything already, decidedly everything. (3.10.10)
Much of the suffering that characters such as Katerina endure comes from their refusal to acknowledge the truth about themselves out of their own pride.
The word "strain," just uttered by Madame Khokhlakov, made [Alyosha] almost jump, because precisely that night, half-awake at dawn, probably in response to a dream, he had suddenly said, "Strain, strain!" (4.5.1)
The word "strain" is interesting; the Russian nadryvat' has been translated in some editions as "rupture." These characters are literally "straining" under their false notions of who they are (and who other people think they are), to the point of rupture or breaking. In female characters such as Madame Khokhlakov and Katerina, this rupture tends to take the form of hysterical fits.
[Katerina] spoke with a sort of strain, in a sort of pale, forced ecstasy [...] "I will be his god, to whom he shall pray – that at least, he owes me for his betrayal." [4.5.10)
Quote #3 from earlier in the chapter has prepared the reader to see this passage as an instance in which Katerina's desire to be a "god" is shown as ridiculous.
"And if the suffering of children goes to make up the sum of suffering needed to buy truth, then I assert beforehand that the whole of truth is not worth such a price." (5.4.21)
Ivan poses suffering as a theological problem here: if sweet innocent children suffer, how can there be a just God? This sounds a false note, though – Ivan doesn't really seem to care about suffering children.
But at the moment he could no longer reason [...] his soul was troubled, troubled to the point of suffering. (8.6.2)
Personal suffering leads Dmitri to lose his ability to think rationally.
"I was a fool, a fool to torment myself for five years! And I didn't torment myself because of him at all, I tormented myself out of spite!" (8.7.182)
Grushenka recognizes at this point that her real suffering was self-imposed; she alone is responsible for holding onto an idealized image of her loser Polish boyfriend for so long. In short, she should have gotten over it a whole lot sooner.
"You can revive and resurrect the frozen heart in this convict, you can look after him for years, and finally bring up from the cave into the light a soul that is lofty now, a suffering consciousness, you can revive an angel, resurrect a hero! And there are many of them, there are hundreds and we're all guilty for them! Why did I have a dream about a 'wee one' at such a moment? 'Why is the wee one poor?' It was a prophecy to me at that moment! [...] All people are 'wee ones.'" (11.4.36)
Dmitri often refers to resurrection during the experience of his trial and subsequent conviction. The language draws a parallel between Dmitri and Jesus, where suffering redeems not only the individual but the whole of mankind (thus Dmitri's reference to the "wee ones").
"Before it was just her infernal curves that fretted me, but now I've taken her whole soul into my soul, and through her I've become a man!"(11.4.51)
Another shift in Dmitri's sensibility in the second half of the novel is marked by his sincere love for Grushenka, which has replaced the purely physical lust he felt for her earlier.
"On the other hand, what about my conscience? I'll be running away from suffering! [...] To run away from crucifixion!" (11.4.57)
As in Quote #8, Dmitri continues to draw parallels between himself and Jesus, here by describing his ordeal as a kind of "crucifixion."
[Ivan and Katerina] were some sort of enemies in love with each other. (11.7.60)
Unlike Dmitri and Grushenka, Ivan and Katerina are still stuck in a love-hate relationship. Neither of them are able to let go of their pride and are consequently doomed to hurt each other and themselves.
And as he entered his room, something icy suddenly touched his heart, like a recollection, or, rather, a reminder, of something loathsome and tormenting that was precisely in that room now. [...] Apparently something there, some object, irritated him, troubled him, tormented him. (11.8.148)
One consequence of Ivan's intellectual pride is that he becomes a religious skeptic. But this skepticism causes him such enormous suffering that he eventually goes mad. In this quote, he encounters the devil.