Do you believe that God is just an idea inside your head?

How do I know that God is not just a figment of my imagination?
Finally, I worked it out. I know.
How can I know?

Read this, slowly...

If you believe that God is just an idea inside your head, then so are you. Pause;
Do U Get it:
If you believe that God is just an idea inside your head, then U too are just an idea inside your head.
You need to slow down and think about that. 
But you know that you are more than an idea. You know that because you have a dick. Or maybe you have a beautiful pussy :-)   Either way, you did not create any part of your anatomy. God did. You do not have a clue how to create a single thing. And yet you are here. Which proves that God was here first.
You are not just an idea inside your head. You are Awareness. That is all you are. And with Awareness comes choice. You can choose.
You can touch things. Do real things.

You are here. You are flowing through a matrix of cells that comprise your body. God designed the matrix. You chose which channels to open and close. Binary options. Billions of them. Circuitry. Which circuits are open, which are closed. And the net result is you. Life flowing through the circuit makes U. And you are aware of all this. At one stage or another, you chose this. Billions of insignificant choices, and a few significant ones, all united, combine to make you. 

You really control nothing except your thoughts - ideas that you believe in - this determines the countless choices you make.

To the extent that you maintain awareness, you know who you are. But once you get into a thought routine, you forget. You go off at a tangent. Searching for something that cannot be found because you are lost and cannot remember your source.