How do you know you're communicating with God?

How do you know that your connection to God, your personal relationship, isn't just a conversation in your brain? Write your own personal explanation using between 5 - 500 words and the author who's response helps me better understand this phenomenon will receive one ticket to the 2015 Wild Goose Festival. ( I purchaed the ticket hoping to attend but I won't be able to make it, maybe next year). Email me at treybien33@yahoo.com by June 18th, 2015. Background: on the continuum I sway between a reluctant athiest and a skeptical agnostic. I'm pretty far from the "true believer" end of the spectrum. But, I keep an open mind. Personally, I can't sense any reality beyond the natural world. So, I'm interested to understand how/why people of faith know their personal relationship with a supernatural being exists as opposed to it just being a dialogue in their mind/brain.