The Warrior Priest by C.J. Archer

A warrior priest sworn to an oath of celibacy, and a spy fleeing from her past. A magical mystery, a forbidden temptation and a destiny they cannot escape.

Jacqueline (Jac) has survived on the streets ever since escaping from the clutches of her ruthless uncle, the city’s powerful governor. He craves more than political influence and believes a legendary talisman in Jac’s possession can give it to him.
To survive, Jac has honed her skills as a thief, catching the eye of Rhys Mayhew, a brother in an order of warrior priests. Rhys enlists her as a spy, and their partnership soon deepens into more. But Rhys’s faith demands strict adherence to oaths of denial, and when he is unexpectedly elevated to the position of master of his order, he faces an impossible choice: his duty or his growing attraction to Jac.
As her uncle’s net tightens, Jac seizes a chance to become an assassin’s apprentice, leaving the city for months of grueling training. When she returns, much has changed—except the forbidden nature of her bond with Rhys.
When her uncle learns of her return, Jac’s life is in grave danger, forcing her and Rhys to unite. Together they unravel the secrets of the talisman and confront dangers both old and new. But the greatest danger of all is to Rhys’s loyalty, as resisting Jac becomes more difficult with every passing day.

NOTE: Although this book is a standalone novel set in the same world as the AFTER THE RIFT series, it can be enjoyed without having read that series first.