Evernight: The Darkest Fantasy
Solace is probably Tarth’s greatest god, and is worshipped far and wide across the land. His divine existence is indebatable; he grants visible divine powers to the many Sun Priests and Red Knights that roam the land, bringing light into the darkest corners.
Even the demihuman races pay respects to the Sun God, if only because of his obvious power.
For some reason, only humans are able to channel Solace’s powers, thus becoming Sun Priests and Red Knights.