The title of this story—Jacob Have I Loved—comes straight from the Bible. In fact, it's a verse that Grandma helpfully quotes to Louise in order to twist the knife in a little further after some bad news:
I could hear the Captain talking on to Mother and Caroline about the academy he knew in Baltimore with the wonderful music program. The words roared in my ears like a storm wind. I put the kettle on and laid out cups and spoons. Everything seemed so heavy I could hardly pick them up. I struggled to pry the lid from the can of tea leaves, aware that my grandmother had come in and was standing close behind me. I stiffened at the sound of her hoarse whisper.
"Romans nine thirteen," she said. "'As it is written, Jacob have I loved, but Esau have I hated.'" (14.85-86)
Seriously, Grandma? Romans 9:13 has meaning for both Grandma and Louise because they know what it signifies: even though Esau was the firstborn of Isaac's twin sons, Jacob is the one who is blessed by God. Why? Well, as the Apostle Paul explains, it's because God does what he wants. He totally dug Jacob but wasn't so into Esau. Louise finally understands the truth—God hates her and her bread is always going to land butter-side down because of it.
Even the title of the book emphasizes the fractured relationship between the sisters by deleting the second half of the verse about Esau all together. "Jacob have I loved"—this may be Louise's story, but Caroline's favored status clearly looms large over it.