I don't believe in a God, but maybe he does exist for the people who believe in him, the human mind is an absolutely incredible thing and if people need faith to help them with their problems than maybe that belief actually drives them to solve their problems thus, "God" helped them in their eyes. You know what else could be construed as imaginary? Almost everything, because at some point it took humans creating something to make sense of it, other than what is physically there. You can say many things are scientifically proven but who created these formulas, who created numbers, we did as people, so we could have made them mean and be anything we want them to be, but because we know and believe it to be a certain way that's just how it is. Take time for example, us as humans see time as linear, because it made sense for us to make it as such, but the only real measurement of time is circular, the sun rising and setting, the seasons changing, but because we gave names to elapsed periods of time, we created linear time. All I'm saying is just because you don't believe and he doesn't exist for you, doesn't mean a God doesn't exist, maybe everyone is right, maybe to every body else everything they believe in is true, and instead of there being one true way, there is no wrong way.