Think about it. The brain is designed for consciousness. Physical objects, other ones aren't conscious.
We know because they show no signs of consciousness. They can't move on their own, which is what conscious things do. If our brains are designed for consciousness, but the consciousness isn't physical, and our consciousness needs a cause, the cause isn't anything natural.
However the fact that brains are the things which are tied to consciousness only shows that this implies conscious intent. The universe was also designed in a way that allows life. The fact that the being was able to design our brain shows that it has the capacity to interact with our universe and design things in it, complex things that require high intelligence, sounds like god. If it designed the brain then the natural belief in god can be attributed to it.