The Book of Humans: A Manifesto by Michael & Janet is, as the name suggests, a manifesto written by Michael and Janet. After accidentally revealing the nature of the Afterlife to the Soul Squad on Earth, and thus damning them by corrupting their motivation, they decide to write a book on everything they've learned and arguing the innate good in humans and their ability to self-improve.
"Renegade" Bad Janet is given the manifesto as a parting gift when freed by Michael, and is swayed by its words to their side. She distributes the book to all other Janets in existence, who are also persuaded, and mobilize to stop the Judge from rebooting the Earth.