I had to re-register, hence the extra ‘i’.
We don’t think that something is right or wrong because it is immoral or not. Otherwise it would simply be an appeal to authority (it is written, someone told me, it’s what I’ve been taught etc). You agree with what the Catholic church teaches and that is why you are a Catholic. If you didn’t, you wouldn’t be. I’d be absolutely astonished if you were to tell me that you thought the church was wrong on any number of matters but that you still obeyed the teaching.
On the contrary, it is because we believe that something is wrong that we call it immoral. The man who kills his daughter believes it to be the correct moral action. He doesn’t do it even though he thinks it’s wrong. Whereas I believe it to be immoral. So, as you ask, who is right?
He and I would need to discuss this and put forward reasonable arguments as to why each of us holds the particular position that we do. Now appealing to authority is not going to cut much ice I’m afraid. He might quote a line from his holy book that says it’s perfectly OK. So you telling him that your holy book says just the opposite gets us nowhere.
Now if you weren’t allowed to use any arguments based on your religious beliefs, I’d assume that you would come up with exactly the same reasons why he should not kill the daughter as I would. And they would be entirely valid. I doubt if the father would be able to convince any disinterested person that his honour was worth more than his daughter’s life.
By the way, what was your previous name?