Because morality changes depending on society, the time period, etc regardless of religion or politics. And moral relativism is a well known subject that you can read about more online; its relative to the millions of factors that determine our morality for us. Its relative to culture, time period, etc which i did explain in the OP. If God exists he sure did not do a good job making things clear or objective; its almost like he doesnt care about objective morality. Plus, how do you know if God exists that morality is in fact objective? Maybe God doesnt care about pitiful human morality? Your entire argument makes presumptions about God that we're not required to accept because there's no evidence or reason supporting it. Don't tell God what to do.
Ok, as I advised a student recently lets define some terms.
There are two very different things called "morality". It is best to define them upfront.
1.
Malum in se (plural mala in
se) is a Latin phrase
meaning wrong or evil in itself. The phrase is used to refer to conduct assessed as sinful or inherently wrong by nature, independent of regulations governing the conduct. It is distinguished from
malum prohibitum, which is wrong only because it is prohibited.
This one should be called morality and does not change with people, time, or geography because they are not created by any of them. The one exception is how they may be applied to each but I will save that for a later discussion. The above is what I and most associate with the word morality.
2. Malum prohibitum (plural mala prohibita, literal translation: "wrong [as or because] prohibited") is a Latin phrase used in law to refer to conduct that constitutes an unlawful act only by virtue of statute, as opposed to conduct evil in and of itself, or
malum in se.
This one is often referred to as "morality", but since two mutually exclusive claims cannot be true at the same time one should be named something else. I would call this one ethics. This one does change by time, culture, and location. You may chose any word you wish for this type of "morality" but to avoid confusion it should be distinguished from the 1st definition.
Lastly, in Christianity things are not right and wrong because God says so. God's eternal nature is the moral standard. His commands merely reflect what his character dictates. However he wished to create creatures with freewill. Freewill is necessary for true love. A kiss from two lips on an iPod means nothing, from your spouse it does. We can either act consistently with God's nature or rebel and contradict him. There is no use for a Euthyphro type argument against Christianity, nor any false optimality claims. If God exists I should expect the exact type of world I find.
Now that things are a little clearer you may re-calibrate and fire away again.