"God" is not a who or a what.
Atheists tend to approach the concept of "God" from the perspective of the widely propagated religious concept of "God".
Mystics have always known that "God" is not a who or a what.
This is why they have said that "God" is nothing and everything. No "thing" (in particular) but everything (All That Is).
Like I said, try and get away from the word "God" because it is rife with so many bankrupt religious connotations. I try to avoid the word as much as possible because it is of no relevance and only perpetuates misunderstanding.
Spirit is the ever growing, ever expaning, ever evolving web of inter-beingness that is wholly irreducible in every way.
Nothing exists in isolation. Everything is defined by it's relationships which are innumerable.
That is what the world is realizing now with the destruction of "the environment". We are not separate from the ecosystem in which we live. It is an extension of us to the point that all divisions blur completely.
Here's an example: Would you consider the beneficial bacteria in your body to be part of "you"? Let's see- you cannot digest food without them, you cannot manufacture vitamins necessary for life without them, you would have no immune system without them. So even though they are not part of your contiguous material body, they are "you".
The entire irreducible wholeness of the web of life, where nothing exists in a vaccum, is "God". There is no intelligent design or creation, because both of these imply an "outside" creator. Order is not imposed externally, it is an intrinsic aspect of unfolding of existence.
We are but one aspect of Oneness/wholeness and absolutely cannot be separated from it in any capacity. Man developed the delusion that he was separate all of life millenia ago, but we are nearing a complete shift in consciousness.
This shift in consciousness is nothing recondite as those of new age spirituality tend to portray it. It is simply the realization that there is no separation between any facet of life.
This is all corroborated by quantum physics. All of the current paradigms that dominate earth- political, scientific, economic, religious, medical, social, etc are based on the archaic belief in dualism and thus, separation. This has been outmoded for a century. Civilization as we know it is based upon a profound misunderstanding, but like I said, this misunderstanding is slowly changing. Our self-definitions are changing, and with this, our "world" and form of civilization will change with it.