Why do so many people believe that religion is entirely an outward reflection?

"inward spiritual relationship to God" You do realize that this 'relationship' is a figment of your mind, right? What you are saying here is that our emotional systems are just as valid as our intellectual systems in determining reality. Emotions are reactions, critical thoughts are proactions. The concept of God is using emotion to fill in the gaps in our intellect. This can be very dangerous to your psyche in practice, as it is a crutch that you will rely upon to make critical decisions. A more healthy route would be to develop your critical thinking skills and use them to replace emotion when making critical decisions.