Human, Fighter/Warlock.
Personal premise is someone who was enamored of the Paladins of his faith as a child, desperately wanting to be one when he was old enough. He was rejected as the clergy found his motivations lacked any significant faith or desire to serve and was more based on pride and prestige. Devastated, he started sinking into a deep depression when in his dreams (at least he's pretty sure it was his dreams), he was offered a chance to serve his faith in other, less conventional ways...by committing to a pact to adhere to the spirit of his faith, if not the letter (a deific servant to the faith did indeed approach him in his dreams with this offer, as some divine servants within the faith feel a less conventional group of faithful could prove useful).
He presented himself to his church, new-found powers and all, ready and willing to serve...only to be branded heretic and all but chased out. The "spirit" that visited him in that dream warned him to expect such, but encouraged him to be honest in his dealings with the clergy and that they were acting within the tenets of the faith and to not blame them...that his own faith needs no acknowledgement, it simply needs to be.
This assumes the Celestial patron is available though lol. Otherwise, I'm undecided as yet.