well its kind of hard to jump into this thread now, specially since i was the one who started it. so i will try to answer a couple of the first things i see..
briefly, to abortionators point about the bible having so many different versions etc etc.  that is a pretty thin argument.  yes there are "different versions" but they're all translated into saying the same thing.  its more so just into different style of writing: king james, new kind james, english standard, etc etc.  some may use different words in different places, but when you look at the literal greek or hebrew translations, you could take either english word from the hebrew.
to amedeus' picture/quote from epicurus and the whole argument of pointing out if God is able to prevent able, or stop this, or what have you.   God leaves it up to us humans to have a choice.  to do evil or not do evil.  if god intervened every time someone was about to do an evil act, there would be no choosing involved, and therefore we would just be puppets or robots.
also, to your answer "moral challenge".  no, there is not one more ethical thing a christian can do thats better than an athiest.  but in the end, what standard does an athiest have to live by? only his own.  so if he thinks its ok to shoot up a school, he will do it.  and at this point, its all relativism. "to each his own", right?  wrong.  being a Christian set your standards and it sets your morals. giving you something to live by. giving you a "mirror" to look at yourself and see the right or wrong that you're doing.
and to put it simply, just because you're "religious" doesnt mean you're "doing it right". the religious fanatics of 9/11 are a good example.   personally, i believe christianity is the one and only true way to heaven.  but thats a whole other argument.