Because if not sorry it makes the action have meaning if he is.
I cannot begin to tell you how unhelpful this circular reasoning is.
How do you know there is meaning? Because people are punished (in some as yet undefined way after we are unable to observe him to determine if he is in fact punished).
How do you know people are punished (in some as yet undefined way after we are unable to observe him to determine if he is in fact punished)? Because there is meaning.
Do you see how the this is a problem?
Can you prove that Odin doesn't exist and that you must be more violent in order to be rewarded?
No because one of the many rules of logic is you can’t prove a negative.
Well you can prove some negatives but you are correct that depending on our definition of "Odin" it is an unfalsifiable proposition. Still if you cannot prove that god agrees with your moral intuition (don't steal/don't murder/don't lie etc) and instead values only marital prowess then how can you justify not stealing and killing?
I'm not trying to judge you or initiate a gotcha here I am just pointing out, at length, that you have the same problem of justifying your actions that I do the only difference is that I am not trying to solve any mystery by appeals to a larger mystery.
IF you cannot be certain what some god(s) expectations of you THEN you are still forced to use you own personal moral intuition to discern right from wrong.
IF you are forced to use your personal moral intuition THEN you must still have some good working standard for what is right and wrong.
This standard, being based on your own personal moral intuition, must by definition be subjective to you.