........then why is there a whole field of philosophy based on ethics? Most of which are completely secular?
Why am I a atheist pacifist that came from a military family then?
I find that the ' secular ' is mentioned at Romans 2:14-15 in that, unless damaged, we are born with an in-born conscience. That conscience can either ' excuse ' or ' accuse ' actions. We can listen or violate one's conscience.
Violate to the point that one's conscience can become hardened or calloused to the point of No more feeling.
No more feeling like skin branded by a hot branding iron - 1 Timothy 4:2
I had, and have, a military family background.
When I first read Revelation19:18 I felt my navy captain cousin was in that list.
He knew things were Not right with the Viet Nam war, but did Not resign yet at that time frame.
Perhaps you might see what I saw: we need to be neutral in the affairs of the world.
Jesus and his followers were neutral, they did Not even get involved in the issues of the day between the Jews verses the Romans. Jesus, of course, is Not a strict pacifist because Jesus, as Commander in Chief, will command angelic armies for us in order to usher in global Peace on Earth among person's of goodwill.