The Memory of Earth

Wikipedia contains spoilers

The Memory of Earth is the first novel of the science fiction Homecoming saga by Orson Scott Card. The Homecoming saga is a fictionalization of the first few hundred years recorded in the Book of Mormon.

Warning: Wikipedia contains spoilers

Humanity has lived for 40 million years in the planet Harmony, after making Earth uninhabitable. In order not to repeat the mistakes that led to the destruction of civilization on Earth, a computer, known as the Oversoul, was left as guardian of this planet.

Its main mission was to prevent humans from developing technologies that could make wars a global affair. For that, humans were genetically modified so they could communicate with the Oversoul. However, after this long time the Oversoul is beginning to fail, and she choses a group of humans to return to Earth in search of the Keeper of Earth, in the hopes she will be able to find a way to mantain power over the people on Harmany.