Trivium - The Trinity of Souls Series, #3

Cast out of Heaven and stripped of their angelic light, Anya and Micah are sent to Earth where they're free to live as a human couple. Considering themselves lucky, they embrace the sentence as a blessing rather than a burden. With little money and no one to turn to, they move in with an elderly woman, becoming her caregiver, and soon learn being human comes at a high price. Stuck in a world where lies, illness and dark forces surround them, their dream of finding Heaven on Earth is short lived.
With the trials and tribulations of Heaven, Hell and Earth bearing down, they must draw on their angelic origins to fight for the love they were never supposed to have.