I wouldn't view a God as "watching" as many Atheists seem to say. "Watching evil."
A participation is essential. God is not a tyrant or a dictator or a controller. In a way he wants to guide, but can only do so through the spirit. Nature is set as a self-sustaining system created at the very beginning. It wasn't created such that it would need constant maintenance.
In fact the systems of nature are amazing, not wasteful, resourceful, cyclic, and better than any human systems that could ever be formed.
But God is not just all these things. There is much more to this energy which we do not see.
Many atheists like to say that we don't need the Bible to be moral beings. While I can be a moral person without my parents, I like to have their advice, guidance, experiences, inspiration and encouragement. This is the same with the Bible and God. Yes, we are humans, we make choices and we should exercise morality, but the Bible and God for most people is simply a source of faith, encouragement, inspiration, hope, love and guidance and companionship. It is this relationship which you cannot dissect under a microscope or analyze on a super computer with computations.
I can dissect your brain and learn how big it is and what parts it is made of and this will tell me nothing of how many languages you spoke, your favorite animals, your character or personality, if you lied a lot or who your best friends were. This will tell me nothing of your ability for maths or architectural design. There is a lot that can only be learned through a relationship, a connection and observation of without you are limited in what you can see and learn. Such is it with nature. If you don't have a constant connection with it, a relationship with it or observe it enough then how do you expect to understand it more fully? God is like this for many.
Bonobos are clearly a very compassionate ape. In fact they are said to be the most compassionate of all the animals, besides humans. We can clearly see that nature is evolving the ability to be compassionate, loving, to b as we would call moral. However to have the ability to be moral and to act morally are two different matters.
The significance religions played in the role of love, compassion, self sacrifice, and unselfishness have to be taken into consideration when questioning the existence of morality. Would nature alone without religion have gotten us to where we are today morally?
A recent scientific study revealed that we can learn to be more compassionate by simply acting compassionately.
So, we can and do change our brain's wiring all the time
Without religions I have to seriously wonder where our species would be on the moral scale today. Not just doing something for someone because it suits you. That is an intellectual decision. But doing someone for something even when it doesn't suit you.
If behavior can change our genomes and genes, than are behavior is changing us from the inside out and it is significant as to all the factors/pressures that are guiding us in the direction of more moral behavior for our future species to become a more moral society.