If you cannot prove that God does not exist then you cannot dismiss the possibility of Creation out of hand as you are trying to do. Science is about truth seeking and if one dismisses possibilities without evidence then one is no longer seeking the truth and science becomes a joke which no one should bother with.
While science can only examine the material world, it can never disprove the immaterial which is very much a part of reality. In fact many scientists have become more certain about their religious beliefs through their scientific endeavors. They have considered their work as the discovery of the way God worked. Indeed, while science can only examine the material world, its discoveries prove the order in the natural world. Such order is inimical to a materialistic viewpoint since it shows intelligence and design in the Universe. Moreover, the product of science - the rules, formulas, equations, and cause and effect relationships formulated by science - have all a totally immaterial nature. This is so because the product of science is information, a totally immaterial concept.