A simple question for theists

[Brian37]

...killing an innocent person goes against Natural Law. Meaning it goes against the way our world works, because that is how God created our world to work. Thus we have an inherent understanding that directly killing an innocent person is wrong.

Exactly that. At the same time, The OP's hypothetical is that you believe the person is 100% innocent. As fallen creatures, we must admit to our own limitations - there is no 100% and so while you may believe the person is innocent isn't it also possible that you are not in command of all the facts and must trust that God's judgment is just?

As for Abraham, remember that God did't actually have Abraham kill his son, but was merely testing him. Furthermore, I personally find it hard to believe that story actually happened in the literal way it was written...Did God's voice sound from the sky and tell Abraham to kill his son, and then tell him not to? My guess would be no...as a Catholic, I am free to take a literal or allegorical approach to the Old Testament stories. I tend to lean to the latter. 

As you know, I feel people should be careful to discern between what should be taken figuratively as opposed to literal versus. In this case, Gen 22, figurative elements are clearly present, however, I see no reason to take this story as pure allegory.

Lastly, Christianity is defined by the New Testament.

Sorry, but I must protest. The NT cannot be divorced from the OT. As per my earlier citation, on the road to Emmasus, the resurrected Christ opened the eyes of his disciples to show them how the Law and Prophets spoke of Him. Or in John 5:46 where Jesus says "if you had believed Moses, you would believe me, for he wrote about me..." Or the story of the eunuch reading Isaiah and not understanding it until Peter explained it to him.  Christianity is defined by both the NT and the OT together as a seamless narrative.

This is the problem with every religion, you cant even get members to agree how to view the writings. Nobody wants to consider maybe that is because there is no God and the people who wrote them had no clue about the nature of reality and each new writer was simply trying to get in on the game to gain fame for being part of writing it. 

Same reason Sunnis and Shiites don't agree. Same reason a Tibet Buddhist won't agree with a Chinese Buddhist whom wont agree with a Japanese Shinto Buddhist. Same reason a Obama voting Baptist wont agree with a Trump voting Baptist.

But I agree, you cannot separate the NT from the OT or even Revelations because regardless of the inconsistencies throughout the book it is still written to defend the head character God. I cannot take a book seriously that has men magically popping out of dirt, has women magically popping out of a man's rib, stories of taking snakes, talking donkeys, talking bushes, treats the sun and moon as separate sources of light. 

The OT certainly is far more violent than the NT, sure. It has God condoning violence to dissent or causing violence of dissent, in infanticide and genocide. Jesus comes along and offers flowers, but not really because he says he is there to uphold the OT. But so what, the head God of the entire book goes right back to being a violent bully at the end. 

That book was written for the tribal kingships of it's time. It has no reflection of today's modern western pluralism and concept of consent of the governed. You cannot remove this character from his position.  You cannot have him impeached. You cannot change his laws. You cannot vote him out of his position. Just like you cant remove a ruling family, a king. And neither of you like Jews want to face the fact that the Yahweh character was stolen from the prior polytheism of the Canaanites. 

Both you and CL cant agree on interpretation, just like our two Muslims here Mystic Night and Atlas cant agree on how to interpret the Koran. How is it you think you are not doing the same thing other religions are doing, having their internal conflicts about interpretation?