The Book of Life is a book in The Sims 4 which Sims can write and use to resurrect dead Sims. Each book can only be used on one Sim, but there is no limit to how many Books of Life can be written by a Sim. It is classified as "The Book Of Life" when picking a book to write.
The Book of Life works similarly to the Voodoo doll, as the player can bind Sims to the object and use it on the bound Sim. Sims with the Book of Life can resurrect any Sim from their relationship panel.
To resurrect a Sim, the selected Sim must first master their Writing skill and complete the "Bestselling Author" aspiration. Once they have done this, there is an option to write The Book of Life on the computer. When the book is written, Sims can use the book to "Capture Epic Saga" of a Sim who has not died. After a Sim dies, the owner of the book can use it to "Summon" the Sim who died.
If the book is used on a Sim that is still alive, the book "invigorates" the Sim, by completely filling all their need bars.
- How to resurrect a Sim in The Sims 4 at SimsVIP