1. In my country we have philosophy lessons (it starts in high school because before that kids are too young to understand stuff and even to be interested in it.
On philosophy lessons we learn about different religions and all their believes, culture etc. for example in Greek mythology (It's at the beginning because it's well known and easy) we can know the stories from their time period but we don't exactly understand them if we don't know the ancient culture. For example something really simple:
Killing in medival age wasn't a bad thing, there was a way it was honorable and all rich people (nobel people) were training sword fight etc. since they can walk so on the battlefield they were the best fighters and could kill/injure few soldiers before they were injured (Soldiers didn't kill knights and other nobel people because soldier that would catch nobel person would get some money from ransom (small % of it because the rest of it is for army leader/general).
So how do we see killing and ransom, "kidnapping from the battlefield" today?
killing is bad, kidnapping is horrible, and ransom is not cool but today it's prisoner for prisoner thing (Guantanamo bay as an example as trade post for prisoners).
Fuck we even discuss if killing injured near dead person is a murder or not.
I would write more but i already made my point and i don't want you to fall asleep.
2. "Every one of us is an atheist to the 5000+ other religions" No. You don't understand what atheism means. ateism means anti-theism so God or supernatural stuff don't exist also atheism assumes religion is against intellect etc.
So for example Islam - There is one God and people that don't believe in this God are damned and if you are sinner but you will convince somebody to your God (Allah) you will go to heaven, the only exception is Atheism, atheists in Islam are like subhumans for Germans ohh wait political correctness: like for Nazis from the Moon are Jews and Eastern people... and everybody else.
Why Atheism is hated in Islam? I have no idea what's interesting they copied that idea from Christians (Like half of religion lol) My guess is christianity is better known to you than Islam because you live in Western world so let's show an example of something that is already known or at least acceptable by society:
Part of christian society (don't know which one exactly) don't accept evolution and some accept so let's talk about the one that accept:
Some people believe that Bible is a metaphor let's say it is (personally i think picking what you like in religion is stupid to me) so now you have a problem is "know" the same as "believe"? If you know something is it still faith?
For example let's say angels are fucking real and you saw one and now you know that angels are real but do you believe in them? In Christianity and Islam if you don't believe in God and everything in Holy Books you will go to hell right? So if you know about angels but you don't believe in them then it's kinda akward.
And again i wrote too much, i made my point and then i wrote more and more and now i have no idea what i'm talking about anymore.
PS: If i'm wrong about Islam and there is any muslim that can correct me about atheism etc. please do it.