This might seem to be obvious, but maybe we forget this when we engage in discussion about what we think these texts mean.
For a start we are dealing with liturgy, not an AE equivalent of the Bible as a complete text, and certainly not a history book.
So we are dealing with texts taken from a larger corpus and used in specific parts of a funeral liturgy. Add to that the issue that while certain texts will get used in the PT of various kings, they did make their own selections to suit themselves and this trend continued all through their history, for instance the Coffin Texts are a selection to suit that particular deceased, llikewise the BoD and Netherworld Books. We may think then that joining all these texts together will enable us to see the full picture, well, to an extent, but we are looking at only religious texts that are used for the dead, it's like trying to discern the meaning of the Bible by studying only the Missa Defunctorum.
Let's take an example, it's the Epistle and is from Thessalonians 4: 13-18
Fratres: Nolumus vos ignorare de dormientibus, ut non contristemini, sicut et ceteri, qui spem non habent. Si enim credimus, quod Jesus mortuus est et resurrexit: ita et Deus eos, qui dormierunt per Jesum, adducet cum eo. Hoc enim vobis dicimus in verbo Domini, quia nos, qui vivimus, qui residui sumus in adventum Domini, non praeveniemus eos, qui dormierunt. Quoniam ipse Dominus in jussu, et in voce Archangeli, et in tuba Dei descendet de caelo: et mortui, qui in Christo sunt, resurgent primi. Deinde nos, qui vivimus, qui relinquimur, simul rapiemur cum illis in nubibus obviam Christo in aera, et sic semper cum Domino erimus. Itaque consolamini invicem in verbis istis.
We can get from this the idea of resurrection and also an Egyptian style euphanism about "those you have fallen asleep", and comments in another forum about this very topic bring this out, and I'm posting here as the IQ levels elsewhere are abysmal and I don't want to waste my time on a post there which would attract cranks, and others. However, even taking the entire Mass we will get a very incomplete idea of what the Bible is about if we had no other knowledge, the position we are in as regards the PT, at least until we get to the various texts, such as Ipuwer, in the Middle Kingdom, but it's still very murky.
We cannot add very much to our understanding of the PT as regards their religion as a whole until we get to the New Kingdom. Here we finally get to see texts and images on temple walls that deal with life instead of death, but, it's still all liturgy, repeated phrases not for the purpose of telling a story, but of praising the gods and magically ensuring that the liturgy continues forever even if there is no priest to physically perform the liturgy.
Therefore, while we can take information from the PT, it only shows us selected elements of their religion as it concerns death, and in a liturgical and magical way that does not have to be coherent as each element, while following a sequence as can be shown with the position of texts in the tombs, deals with just one specific element, ie, as has been pointed out by just about all the translators over the years, it cannot be read as a book from the first to last chapter, hence the ordering of the texts by Allen in his translations that deal with them thematically.
Can we ever really properly understand these texts, even though we argue about them at times as if our lives depended on it, or even book sales, I think not.