Shirley, Goodness, and Mercy by Debbie Macomber

Alone at Christmas, Greg Bennett feels his life has been a waste. Sixty years old and he has no one to spend Christmas with, no one who cares.

Greg knows he's made mistakes, hurt people, failed in all the ways that matter. As a young man, he fathered a child he never acknowledged. He deserted a friend in his hour of need. He abandoned his own brother, whom he hasn't seen in years.