The world you see isn't the world you perceive. If it was the world would be completely upside down sense the eye physically inverts images. The brain conveniently inverts this image for your conscious awareness. So if the brain can completely invert what you perceive, what else is it capable of? The brain can alter your perception of reality. For example I have eye damage in one eye. Basically a straight line physically is wavey. I can see it if I close my other eye. However my brain takes the image from both eyes and creates a straight line for my conscious awareness. My brain does a lot of work behind the scenes to create a straight line that I can't actually perceive.
You can't, by definition, be aware of the subconscious mind. Whatever you are conscious of is not the subconscious mind. What you are aware of is the thoughts and images it passes to you. Feeling, emotions, etc. You are only aware of 2 to 5% of what's going on in your own head. However this is the entirety of where our consciousness resides. So we tend to feel it is the entirety of what is in our head. The vast majority of your brain you will never have conscious access to.
Fair enough, you have to decide for yourself what amount of evidence is acceptable. Any belief, concept or something accepted as fact by a majority of folks, one can find a reason to question the truth of.
I guess for me if I can verify something works consistently it's useful. Whether it's the truth or not.
Can a belief in God work consistently for you? Sure. In fact I found it so consistent that it didn't matter which God. One God or religion is as good as any other. I found that with enough conviction my mind is capable of creating the experiences necessary to support that belief. Same as it's capable of creating a non-inverted world for me to perceive.
I've perceive a lot of things that couldn't have physical reality, like the mirage. The perception is real, the image you see however doesn't have physical reality. Is it true, is it not true? Doesn't really matter to your perception or belief. You perceive it, you believe it truth is irrelevant in this case.