Why is there suffering in the world?
I can't say for sure, but...
“I believe like a child that suffering will be
healed and made up for, that all the humiliating absurdity of human
contradictions will vanish like a pitiful mirage, like the despicable
fabrication of the impotent and infinitely small Euclidean mind of man,
that in the world’s finale, at the moment of eternal harmony, something
so precious will come to pass that it will suffice for all hearts, for
the comforting of all resentments, of the atonement of all the crimes
of humanity, of all the blood that they’ve shed; and it will make it
not only possible to forgive but to justify what has happened.”
-Dostoevsky, The Brothers Karamazov