Maybe the "suffering in hell" is meant metaphorically because you will feel so much guilt for the pain you caused or regret for not having asked for forgiveness, and some people only realize that when they're older and wiser.
I honestly don't think that anyone should be offended by that quote in the beginning. Sure, you can understand it as in "you don't need religion" but I since there are a lot of people that aren't religious, why shouldn't they have morals? Empathy is a really important part of being human.
Thanks for writing this, it made me think :)
Thank you @tripswithtam. The quote alone got me thinking so I'm glad that it had the same affect on you too. I suppose as we get older we realize more about how what we've done kind of adds up. Interesting way of putting it.