One set of Sacred Texts are known as the Coffin Texts.
"The Coffin Texts, which superceded the Pyramid Texts as magical funerary spells at the end of the Egyptian Old Kingdom, are principally a Middle Kingdom phenomenon, although examples have been found as early as the late Old Kingdom. They democratized the afterlife by removing the royal exclusivity of the Pyramid Texts."
http://en.wikipedia.org/wiki/Coffin_Texts
This point concerning how the conception of the afterlife was "democratized" is very important. It is a CONCEPTION of the afterlife, which some falsly mis-interpret as a reflection of reality.
For example, this is what leads some to interpret the symbolism of hue-men and "pigs" (for example) living in "harmony" in certain artistic depictions as a reflection of "reality" while the fact is the "pig" was reviled prior to the supercession of the Pyramid texts and was seen as an "evil spirit", which laer was "deified" when the "Sethians" arose to ascendancy within the Egyptian nobility.
"In some cases these descriptions were supplemented by illustrations and maps of the underworld called "The Book of the Two Ways".
It is very critical to KNOW how this Book of the Two Ways changed the ancient Egyptian conception of the Afterlife, and HOW this was integrated generations later by the Egyptian Coptic and Ethiopian Orthodox churches and codified into the Two Ways, represented by the Biblical Old and New testaments...the Two Ways, the Old and the New.