The Color Purple by Alice Walker

This book is written as a series of letters. First, Celie, a poor black girl is writing letters to God, then later, she writes them to her sister Nettie. Shen never gets replies to the letters so they are more narrative than conversational. Celie is raped and abused by her stepfather, then later married off to a man who also abuses her. She meets and falls in love with Shug, the woman her husband loves, and Shug helps Celie learn that she is a worthwhile person. Later in the book, we learn that Mr._____, Celie's husband, has been hiding Nettie's letters and when she finds them, she begins reading them and we learn her sister's story as well. The stories intertwine and through them we see all the characters in the story grow and change and go through a lifetime of hurts and healings and emotions.
I like that the characters are neither all good nor all bad, but rather just human.