There is no point in proving God exists or not. Except in providing an argument for one's own point of view regarding religion.

Complexity certainly can not be used as proof. If it could, we could call our selves gods. The reason is, the things we understand and build are vastly more complex than what we could ten thousand years ago. If a man from those remote times could see our way of life and the complexity of it, they would surly believe we are gods.

The only way God can be proved is by God proving its self. No matter what efforts we take through thought or physical action, the results can never be thought of as absolute proof for all people.

We, as living beings haven't been around that long. Not when you compare the age of the Earth or of the universe. The knowledge we have gained so far is small when you consider how much there is to learn. We are still in our infancy as a species who can learn. How could we be expected to prove or disprove such a thing as God with our limited knowledge?

For them who wish to believe, let them have that. It brings them comfort in times of hardship. It brings them joy to think they have been blessed.

Our lives are so short. We must find comfort and happiness where we can. The notion of God brings that for many.