>>1519143He didn't, as far as we know. No evidence points to a creator, other than religious texts which are easily proven to be untrustworthy.
Btw, what makes you think Earth is the only place with life? The closest solar system to ours with a habitable planet is so far away that it would take generations for any message to travel there, and generations for a reply. We've only been able to send and receive these kinds of messages since the 40s, that's not enough time.