How do you know?

I have a question for the believers -- the "I don't think, I KNOW" croud.

How do YOU know YOUR God exists?

and

How do YOU know THEIR god does not.

our belief stems from the one living god and do no worship gods of stone or wood for that is what they are (just wood and stone). how do we prove the existance of the living god, its written in our hearts and the words we have in the bible are for our guidence as to how to live. Pray this helps.