There are many that claim that God is not, simply because they do not see Him. I say that He is because He has left ample evidence as to the existence of His person.
Could someone claim that I had no father simply because you cannot see him? That would be absurd, complete outside of reason, because by seeing me, you see the necessity of my father's existence. You can even find His identity in my DNA. Even so, you can find God in His creation. Things to not cannot come from nothing, springing up of themselves. An animal or even a plant that has design, order, and function is no random object. There must have been a maker. You can even find His identity in His creation; for His children are made in His image.