The difference between ethical atheism and nihlism is that ethical atheists have more faith

[Question Mark]

I don't see what theists could have against arbitrary morality. That is after all what all morality is, especially religious morality. The only difference is that secular morality is based on man's experiences and reason, and religious morality is supposedly based on what god says.

Secular morality: Murder is wrong because it deprives the victim of their right to live, and has demonstrable negative effects on the people the victim is close to.

Religious morality: God tells us that murder is wrong, and so therefore it is.

Nothing that you said even remotely addresses the very serious questions raised by the post. Where does the victims "right to live" come from? To be an honest atheist means to reflect on the nature of these concepts. Is your knowledge that there is right to live stronger than your belief in absolute, unguided atheistic evolution as the means by which life was created? I do not think you can have both.

Let's not bandy about divinding concepts of "honest" atheists and the like, or shall we start calling christians "honest" christians, and "reasonable" christians and the like. Christians and atheists will do fine I think.

What I said here addresses the overarching problem of these questions. Secular morality looks at the effects certain actions have upon other people, by individuals and groups.
The right to live stands, in this context, on the fact that as atheists, we believe that there is nothing after we stop living, therefore removing one's right to life removes each and every other right they have as well. And it's irreversible. Once they're dead, there's no returning their rights to them.
We ascribe rights to people because we ourselves want them, and feel bad when they're taken away, and the best way to not have them taken from us is to make sure no one else feels like they're getting their taken away.

Why do people have a right to live more than ameobas? You may say "because people feel pain". But there are a million other considerations. What it is about people that makes them special?

We're biased towards our own kind. Is that so unusual in the human race? We show preference for individuals we share sympathies with all the time. We have little in relation to amoebas, so we don't consider them as important.

Religious morality and secular morality are totally different. Religious morality says that people are created with a certain nature, and to disagree with that nature is to rebel against God. Things are not only prohibited because God forbids them, they are prohibited because that prohibition is part of the divine order of the universe that is established.

You're missing out the fact that according to your theology, god made that divine order, so it is still just him saying something and it being so. There's no reason behind it, it's just god's arbitrary say-so

Secular morality simply invents categories, although usually those categories are related to Judeo-Christian values and past precedent, and are worth taking seriously, even if you are nihilist. But practically, there is no reason to accept those categories and believe they have more authority than some other category that you invent

Believe it or not, the religious categories were arbitrarily created too, by the people who wrote the holy books. The only difference is that secular morality updates itself, where as religious morality has an annoying habit of staying constantly the same whilst the rest of society has moved on.

As I said before, secular morality is created, yes, I acknowledge that, it's not always just been here. but it's a testament to humanity in my opinion that we have taken the time to actually give ourselves morals, to stand up and say that murder is wrong, that stealing hurts others.
To invent a god and make it the reason we have morality instead of our own compassion and empathy is in many ways lazy and cowardly.