This is not a logistical problem in the slightest.
If naturalism is true, there is no objective standard by which we can separate the worth of one proposed system of morality from another, and we might as well use religion as not.
If naturalism is
not correct, then we've got some work to do, but we can start from our common moral intuition, reason, and whatever evidence might exist for the competing religious claims, and there's at least the theoretical possibility of getting the right answer.
This is what you say, but this is not how you behave.
Science can provide a theory as to why other people think of his actions as wrong. Science cannot tell us why his actions
are wrong, or why he
ought not do them.
Now you're back to "proving" that strawberry ice cream is the "best" flavor by pointing to brain scans that show that people eating strawberry ice cream have more pleasure centers engaged than those eating chocolate, and that strawberry uses more taste buds, and that polls indicate more people choose strawberry.
You can measure the brain activity of people that are doing something society considers "good", and you can find, for example, that the brain releases oxycontin in those scenarios, but there is no instrument science has yet devised that tells us what someone
ought to do.
To be precise, though, I am not exactly defining objective in relation to God. I am asserting that absent God (or at least some form of theism), objective morals and duties cannot exist.
This is an especially relevant point in this discussion, because it was you that initially made the claim that secular morality is superior to religious morality, which puts the burden of proof on
you.
It is not up to PeterMP or me or Prosperity to prove that religion is right, or even that objective morals and duties exist. It is up to
you to demonstrate that your assertion is true, and that your proposed system of morality is better than Catholicism, for example.
The ironic thing is that in order for you to prove your point, you'd have to establish objective morals and duties exist (which is the only way to get "better" as more than an opinion like ice cream flavor preference), and this would pretty much defeat the naturalism you seem to hold to.
