Because it's not just about you - our survival is massively increased when we gather together into larger groups and can pool resources. If you steal cows, you get kicked out of society and your survival odds are reduced.
Society is a function of natural selection and adaptation - we've partially usurped the individual nature of survival to include not only social structures, but empathy/sympathy/guilt/trust, brainpower (to make shelter and agriculture to minimize our seasonal and disaster susceptibility) - etc.
there is a ingrained sense of morality that we all share and thos that dont
Therefore it is not actually an ingrained sense of morality that we all share. There is a sense of morality shared by all those who have been effectively socialized by the society that they are raised in. In the cases of sociopaths that system has failed and they are lack a moral sense.
Unless of course you're willing to argue that God has placed an ingrained sense of morality in all people except for certain individuals whom he deemed unworthy, in which case God is not omnibenevolent. Or, you could argue that he placed this sense in all humans but failed with or forgot certain individuals, in which case he is not omniscient. In either case such a god is not God in the Christian sense.
Pure natural selection isn't always just about individual survival - but species/society survival is a factor. If you cannot trust your fellow tribesman, your tribe falls apart, and you don't stockpile enough food for winter... everyone dies. Guilt/Sympathy/Empathy are can easily be explained as evolutionary necessity, without resorting to inventing gods to invest us with them.
Hawk and the nightingale...
Not necessarily. If enough people (lesser strength fellows) get together I'm sure they could take out the 'strongest' guy.
so if these rules establish order there had to be something to estabalish these universal laws.
We know that these constants are observable to us, and appear to have been more or less consistent across the known universe and its observable past. Anything beyond that is speculation. We don't know why they are what they are (except that in some cases, if they were otherwise we wouldn't be here, but it might be that they appear to be constants because that is the only way we can perceive them - they may actually be otherwise), but there are scientific hypothesis that offer just as much, if not more explanation than requiring a god to set them in place. Adding a supra-universal being of unknown power (much less that we know specifically which one) to get it all going isn't an answer - just more questions without a way to test them.
It's like asking what was before the universe. We don't know, and nobody does. Did a god set the universe up? What was before god? If god can be eternal, why not the universe? All we know about the big bang is that it happened, we don't know if there was "nothing" before it, or if it was breathed into existence. Anyone who claims to have an answer, had better have pretty robust evidence to back up. Of course, I recommend that we still keep looking. :)
Turtles, all the way down.