Let's just say, you know for a fact that eating children is wrong. A great number of people believe as you do and we all acknowledge it in unity. Then there is a website that says that eating babies is fine that you don't need to "buy into it" and believe that eating babies is wrong. There are a couple of blogs that talk all day how liberating and fantastic eating children are. Now whoever listens to them think they are crazy and very wrong but a few listen to the intellect behind the reasoning, they listen to the argument. Let's say the argument says it's natural for many animals eat their young in nature, and people are just a part of the natural process or something like that. Some people buy into it and start doing it.
You struggle everyday as to why people think like that, they all must be crazy, what do they know that you don't? This goes on and on but after a while you get curious. You then start to go around thinking why you don't get to eat babies as others do and how some people demand that you don't, like your parents. Then one day you get an opportunity to do it but everything in your soul KNOWS it is wrong. You shake at the thought of eating that very young child. It's agonizing to you for quite a while, you cuss at yourself for having such insane thoughts!
One day you see a little 5 month old at some playground and you convince yourself that you have to know what it's like. You seize the moment and kidnap the child. You keep that child isolated for days agonizing whether you should do it or not. You almost feel yourself slipping away into insanity to the point you can't take it. So you get the nerve somehow, and do it. Then afterwords you say to yourself that it was too quick that you need to try it again to see if the feelings you had during were genuine. So flash ahead a month and you have done it many times and you now frequent places that do it and go online to websites that also do it and you feel a sense of a warm community. You struggle with the nightmares until they pass and you feel OK. You embrace the fact that you are now a baby eater and you and your new friends are OK with it. The struggle get's a little easier to accept the notion that eating babies is fine for the natural process. You teach you own kids that it is perfectly natural to eat babies. You start your own website that is called "Atheists eat Babies!" and you showcase your work.
"Atheists eat babies."
An atheist may still be moral and say murder, rape, and eating babies are wrong; but when asked why, they will not have a final reason, or authority, to which they can appeal to, besides their own subjectivity. So it is merely a personal choice not to.