In Earth's Defense - Larry W Miller - Bog

The Gods are afraid. For countless eons, the ancient Gods have maintained their security throughout the universe by keeping the citizens of each planet oblivious to their existence. Long ago they set up a web of watch-dog guards known as Sentinels to monitor for forbidden knowledge within a given culture. When the people on a monitored planet discover the hand of God, that planet is wiped and reseeded to start again. This has happened to Earth before resulting in the loss of all the people and the dinosaurs that roamed the surface of the little Blue-Green planet. No planet has ever had to be wiped twice. But events on Earth take a sour turn and a Sentinel is dispatched to ascertain the threat level of our world. Cody must convince the Sentinel that the knowledge that mankind possesses is harmless or lose the entire population of his home to the Sentinel's wipe. Can he change the minds of Sentinels and Gods alike when they have been following their rules steadfastly for eons? If he can't there won't be an Earth left to come home to.