It doesn't take omnipotence or a foundational perfect goodness for a ruling body to derive a system of fairness.
Of course people are imperfect. What is perfection anyway, other than an unacheiveable goal.
Instead we must seek a decent system, and then look to make it better, and then look to improve on that, and then seek out the chinks and flaws and address those, and then find the rough edges and look to polish them up. I hope you get the idea.
We don't just throw our arms up in the air and give up.
We find something that is better than nothing, and that is our starting point then we iteratively improve on that.
If you have two children of the same age, the same wants and needs, do you hug one and yell at the other? Do you always let one of them choose the meal, toys, channel and never let the other one choose? Do you decide based on the shade of pigmentation of their skin, which one should get your loving attention and which one should not?
You do not need a god to tell you whether to treat your kids with equal kindness, equal love. All you need to do is think, and empathise. If you can't do those two things then perhaps you will struggle to be a parent and struggle to be a leader. If you need a god to tell you how to behave then perhaps you have not yet reached the level of maturity, self sufficiency or independence of thought that typically comes with being an adult.
If you are still struggling to understand from where do mature adults get their ideas of fairness, of kindness, of being able to make decisions then either you are reaching for reasons to believe a god is necessary for guiding humanity, or you are showing your colours that you personally can't think about what is good and how to behave nice without having a "father" figure telling you what to do and how to think.
Free will is not about doing as you are told. It is about living, experiencing and making difficult choices. It is about growing up and being humble enough to be retrospective and introspective, about being smart enough to consider the consequences of your choices. About being strong enough to forgive yourself for mistakes rather than being paralysed by your fear of making mistakes.
There is a distinct difference between the following two statements:
- I treat others the way I would like to be treated because that is the type of society I would like to promote and live in.
- I treat others well because I believe god wants me to behave that way.
One statement is that of a wise and responsible understanding adult, the other is childlike, doing what they are told but not understanding why. One approach is a journey of learning and progression, the other is of stagnation and obedience.
These paths are mutually exclusive.
Which path would you want your children to follow?