I have a very simple moral system that works, it comes from within, system that most passionate human beings would say is worth following.
My moral principle is this: "If an action causes harm to any living organism, that action is immoral". Please explain how this principle is incompatible with my denial of God existence.
My one liner moral system suppresses defection without reliance on a supernatural stick. Not sure what is your point. You still have not answered the question of morality, where do you get it from.
How do you determine if an action is moral?
I think your moral rule is a good one overall. If instantiated it is not that different from my own primary principle. I think it could use a little fleshing out. We cannot not harm other living organisms and continue to exist for example, but I think you could overcome these deficiencies with some clarification or subordinate principles.
The primary principle I follow goes by many names. It has been referred to as The Golden Rule, Biblical Law, and Kants categorical imperative. They are all variations on the same concept. Some have taught this rule with more clarity than others but the rule can be found in many places.
Christianity: Jesus
"So everything, do to others what you would have them do to you, for this sums up the Law and the Prophets."
Judaism: Hillel the Elder
"What is hateful to you, do not do to your fellow: this is the whole Torah; the rest is the explanation; go and learn."
Islam: Abdullah ibn Amr Al-Ass
"Whoever wishes to be delivered from the fire and enter the garden should die with faith in Allah and the Last Day and should treat the people as he wishes to be treated by them"
Philosophy: Immanuel Kant
"Act only according to that maxim whereby you can, at the same time, will that it should become a universal law.
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The biggest difference between us is that you appear to take the position that your rule stands alone. That it is necessary and sufficient.
Do you claim that you always live by your rule and never deviate from it. Do you manifest this idea and embody it perfectly in this world? That is impossible you are human prone to weakness, temptation, fatigue like the rest of us. Therefore you cannot live up to your own moral code it is impossible. The best you can do is approximate it.
God helps humanity better approximate both your moral code and mine. I highlighted this in my claim number #7 and claim #8 above.
https://bitcointalk.org/index.php?topic=1373864.msg36246134#msg36246134Therefore rejection of God is immoral under both your value system and mine as it leads to an increased failure to live up to the moral code.