[I brought up this analogy in my "God's Atrocities" post, and I liked it so much that I decided to just do it as one post and expand on it.]
Consider this scenario:
You are a six-year-old child, and one night your parents tell you that they are going out for dinner. They tell you that they have hired a babysitter to look after you, just like any parent would do. However, they tell you that the sitter is not actually coming over to the house to watch you. Instead, the sitter is going to be keeping an eye on you from across the street. Your parents insist that even though you can't see or hear the babysitter, the sitter can hear and see you. You have never seen this babysitter before. You've never communicated with this person in any way whatsoever, whether directly (in person) or indirectly (phone call, texting, email, fax, skype, etc.). You don't know this person's name, or even if the person is male or female.
At most, your parents give you a brochure that discusses this person and what a great babysitter he or she is. It even comes with testimonials. However, the testimonials offer very little, contain contradictory information about the sitter (for example, one says the sitter doesn't get angry easily, but another talks about how the sitter has been angered numerous times), and only the first names of the testimonial authors are given (very common names, like "Matt," "Marcus," "Lucas," "Johnny," "Pete," "Dave," etc.). And ultimately, the brochure could in fact be fake. So with that, your parents leave you and go out to eat.
I think it's pretty obvious what's happened here. There clearly never was a babysitter at all. Your parents just wanted a night out with each other and didn't want to spend money on a sitter. So instead they just whipped up a fake brochure about some babysitter and put fake testimonials on it. And now the main question: if you can tell that this scenario is BS, why do you think any different of the idea of God? Have you ever found it odd that God has never spoken directly to you or anyone else? Don't you find it just a little bit strange that your main piece of evidence for God's existence is a book written thousands of years ago by unverifiable authors? As humans, we put our trust in those we know for a fact exist and can safely put our trust in. That's a burden everyone should meet. But God has not done this. So why should we bother trusting him and believing in him? In the beginning, mankind couldn't account for what existed in the natural world. They needed somebody to take care of them and the world. So they simply made up their own nonexistent babysitter to explain it all away.