We believe because it gives us faith. It gives us the willingness to go through our day, to keep the existentialist threat of meaninglessness away. We believe because we crave to be seen, to be known, to be understood. We believe because that is the only thing we can do. If there is no one to judge us - to tell us that we are good, and that if we are bad, we can be redeemed - why bother living at all? Why bother being good at all? If there is no one to look after us, and we are truly alone in this universe, what purpose do we have? We have nothing but the present moment, and only temporariness.