It's better to be virtuous and not have children, because virtuous people will live on in heaven. Okay, now I want this to be a part of the regular bible. Ungodly people's children don't thrive because they don't have roots, even though they may reproduce for a few generations. Bastard children are even worse: a symbol of their parents' wickedness.
A man who gets old has pleased god and only dies quickly so god can get him away from the sinners. Righteous dead people can condemn sinners and god will throw them headfirst into something. It's not specific about what, exactly.
When sinners die, they have to face their righteous neighbours, who will remain annoying until the end gloating at them from the front gates of heaven. At that point, they'll realise that being rich didn't buy immortality. Then there are a bunch of metaphors for ephemerality involving birds and smoke.
Righteous people will also be able to instruct go to attack the unrighteous with lightening bolts, hail, floods and gale force winds.
Kings should know that god put them on their thrones and he can also take them off. No man is greater than god and to paraphrase Tywin Lannister, any god who has to say that is no god. Anyway, the way to be a good king is to stick to the feasting schedule, follow the laws, and become wise, though this book will be of no help to you in achieving that.