Funny, we have the same topic in this strange class called religion...
Simul iustus et peccatorStrange indeed...
In this case I would recommend Jean-Jacques Rousseau and Thomas Hobbes.
Both talk about this topic, from different points of view, but they also include how the state should work to prevent or help or whatever. Not sure if that's what you search for. Like Hobbes, who says "HumanZ !s evilZ!!!" and state has to make them behave(so called "Leviathan State" or whatever term your language uses), or Mr. Jean-Jacques
*, who says stuff like "Everything god made is good, everything becomes bad under humanity" and so on...
Well, if you really want a book, take a look at Rousseau's "Emile"(1762), I didn't read everything, but contains all that stuff.
*Did I mention I love the french language, even though I'm not very good at it? It just sounds so soft and romantic, you can even say stuff like "Voulez vous couché avec moi"(and I know there are typos) and it still doesn't sound rude heh. I would have went on taking french courses, but I'm to lazy to learn vocabulary for yet another language... 
And if not, just do as Kyro said: It's a friggin point of view, like, we think Suicide bombers are evil, but they and their fundamentelistic friends think it's good(yea...whatever).
And about Religion, I'm sorry to say that I don't really like people that I will burn in hell because of what I do without knowing me, instead of knowing only one action that is, for them, against god. If this judging based on the Bible and not their own is not evil, I don't know what is(I hate those orthodox Christians....friggin homophobes).
