Why do you believe in God?

If I was to say there was an undetectable (invisible, yielding no heat, sound, no human way of detection) goblin, who is in your room watching you type each letter, click each click- in fact he is the internet goblin, he controls each and every stroke on the computer ever made- you couldn't prove it wrong. Despite the fact it is illogical, might (if I developed a following) deter a few paedophiles and watchers- it cannot be proved false. Of course we don't need such a goblin to act as a moral comp of the internet and of course it is a load of bullshit- the fact is that we can never know weather it exists or not. Such is true with God- you can never prove him fake. Why should I beleive in this supposedly more realistis version of my internet goblin?