I remember, for example, a passage which began with "Above all, do not lie to yourself ..." which Dostoevsky explains, via one of its characters, that if we are not honest with ourselves -even, relations with the other is found in biased and that this leads almost certainly to hate.
Another passage struck me: one where Alexei saw a group of children pitying and full of guilt before the unjust death of an outcast (I do not quite remember the exact context) asks them to Remember all their lives feeling that they collectively experience this time.
I meditate more often these passages (and many others) ...
I'll have to reread this masterpiece!