The last book looked into the Biblical promises of life and joy for the City of God. This book looks at the promises of destruction and hell waiting for those who continue in rebellion. (The last chapter will look to heaven itself.)
It's hard enough to believe in resurrection, let alone resurrected bodies that will be able to suffer for eternity. This is contrary to the evidence of those animals (a worm specifically) which currently live in fire--are we not better than worms?
We know that it is possible to suffer eternal pain, because there are those in this life who suffer pain but who do not die from it. How much more will that be the case with a resurrected body?