what are we supposed to say again when christians ask us where we get our morality?

[GrandizerII]

The problem is you don't. Therefore, an inaccessible/unknowable source of objective morality is pretty much an equivalent of a nonexistent source of objective morality. You have no objective morality there.

I don’t? Simply because you say so? You’ll have to do better than that.

Not really. All I have to say is you don't have the evidence. If I'm really wrong, then you should show me that I am.

So since you don't have access to that source objective morality, you have to rely on your own thoughts and understanding about what constitutes right and wrong, even if they are based on what the Bible says (or, rather, your interpretation of it).

Yes that was absolutely acceptable because God decreed it. The Amalekites were brutal towards the Israelites after they left Egypt and God vowed to destroy them for their sins (Exodus 17), He has the right to use the Israelites to do so.

So it's absolutely objectively right to kill babies? And how do you know it should only be the case when God decrees it? Seems to me you are relying on your interpretation of these passages in coming up with these moral standards.

Let me put it another way:

If another Christian slaughtered some babies as punishment for the wrongdoings of their parents, and he justified this by saying that it's objectively right to do so, then on what objective basis can you argue that he's wrong? From your subjective interpretation of the Bible?

As are God’s decrees in scripture. Why is it an objective fact that 4 is an even integer when there are people of the opinion that it is not? You seem to think that a person’s opinion can affect the facts so why not this fact too?

For one, these decrees in scripture have not been shown to be from God, let alone the fact that his existence has yet to be demonstrated.