RE: Abraham and Isaac
The point here is that blind obedience to external moral authority can lead to some really horrific actions. If you have an internal moral compass, if you can see pain, fear, and suffering in someone else's face and feel something move inside you, you no longer will care whether otherworldly deities exist or what they want.
Would you really try to slit your own son's throat because only God can save you? Is that what it means to be moral in your world? Is the promise of reward of presents in the after-life the only reason you behave yourself?
It's the difference between a little kid who only cleans up his room, bathes regularly, and doesn't pull his little sister's hair just because mommy told him and he is afraid of getting whupped or for the reward of getting presents from Santa at the end of the year, or a more mature adolescent who knows the value of doing or not doing things for their own intrinsic value. Once he matures to that level, he knows right and wrong, regardless of what his mom says. And we all know moms, and otherworldly deities, can sometimes just as easily command some pretty horrific things, as they can to clean up your room. If you blind yourself to you own sense of morality and let others, including supposedly otherworldly deities, guide you around like a blind man, they will sometimes take you down some pretty blind and dangerous alleys. There is no substitute for opening your own eyes and learning to trust them.
opcorn2: