Scientific knowledge versus spiritual knowledge

[Angrboda]

Maybe I'm missing something here, but why can't the Creator decide morality?

The why is in the conclusion. It's nature is eternal (God is eternal and the source of morality) and morality must be eternal necessarily. The question is how does this argument lead to that understanding? I think I've explained this many times. So perhaps you point out what you are not understanding, where exactly are you not leading up to that conclusion.