Anything is possible. Anything. However, we'd still be trouncing through the woods with sharpened sticks if we treated every possibility with equal consideration. In order to get anywhere in life you have to focus on that which is supported in some way by evidence. If I assume unicorns exist simply because I cannot absolutely prove that they do not, well, I'd be an idiot, wouldn't I? Show me a snapped horn lying next to a set of hoof tracks and I'll agree that they might just exist after all and I would consider further research. Until then, I frankly don't care how much faith you have in unicorns or how you just KNOW unicorns exist or how you once saw a unicorn when you were all alone. By extension, I do not believe gods exist, nor do I entertain the possibility that such things exists. The day someone brings me evidence is the day I consider that there might just be a god after all.