Broken - A Paranormal Thriller by Delena Epstein

http://www.amazon.com/dp/B00K1F4LY0

Amanda Morgan is not your typical twenty-three-year-old woman, instead of becoming the artist she had always dreamed of becoming; she discovers that she is half-demon, half-angel.

Apparently, her birth was planned by God and Lucifer for her to become a Custodian, someone who presents bargains to unsuspecting people granting their great desire, however they are unaware by doing so they lose their souls. Appalled at this arrangement, Amanda makes her own deal with Lucifer, she will present the bargains only if she can tell them both the positive and negative sides of accepting. If she loses more souls than she wins, she will forfeit her soul to hell.

Amanda's biggest problem with this arrangement is that she has no idea of what heaven or hell or like and until this all occurred she had been an atheist. She makes an arrangement with God to visit heaven and he arranges for her to see hell.
However, Amanda is in danger. A demon has placed a bounty on her head, although she is immortal they can inflict serious damage or they could turn her over to Lucifer to earn his favor. The only one she trusts is the man she loves and her best friend, Father Samuel O’Flannery, God's liaison and her best friend.