Without mankind around to believe in him. How can God exist if their is no one around to praise his existance?
Well, for one thing, there is a heavenly host that we know praises him day and night. Plus, they're holy, more suited to His nature. It was only His kindness that gave you or any of us, life.
Personally, just a thought, but I've always wondered if God made an investment in us, to accumulate a net "goodness" from humanity. And too, whether our end may come if God tires of waiting for this investment to pay off.