What were the reasons for the birth of the creation of this universe are still a mystery for the scientists as well as the so called firm believer of God .No one knows the exact planning of this creation .It is just the reasoned thinking we are calling ourselves athiests and thiests .The theory of nothingness is widely accepted by both the communities .It is just like that a seed came first or the tree because a tree is grown with the seed and the seed is grown from the fruit of the tree which came first is still not known and matter of the following which theory we like to follow.
Similar is the theory of athiests and thiests it is just a matter of the following which theory you like most.
I think it's important to understand that when a phenomena is looked at from the scientific viewpoint, the very LAST THING to attribute as causation is "the Work of God (you fill in your version)." In fact, it's more typical that if the causation is not understood or is unknown, that will be simply stated as such.
It's only with the emergence of this method of thinking in the 17th century, that Europe pulled itself out of the medieval mindset and we started to progress in many ways.
Further, note that often it's the mark of a lazy mind to flippantly attribute God as cause.