Darnell Johnson considers The Sanctuary as a prequel or a spin-off to his first book, The Purpose of Life, which basically has the same purpose-of-life mentality but in a different way, more like the guardian-angel-effect style; while The Purpose of Life is something Michael had to go through to understand it. Anthony in the Sanctuary does not know his purpose, and Chayo found out from God both their purpose, but Chayo could not tell him because the only way Anthony and Chayo could fulfill God's purpose for them was by Chayo protecting them both from the evils and ills of one of California's worst prisons.