I've posted here before about connections between Egyptian purification rituals and Christian baptism. viewtopic.php?f=3&t=4524&p=91583#p91583
http://www.academia.edu/26048525/Baptis ... nd_Sarapis
The following quote from "Death and Salvation in Ancient Egypt" by Jan Assmann supports what Brook Pearson says in his paper.Because of the interest New Testament scholars have had in Rom. 6.1-11, the question of baptism in the Isis/Sarapis cult has received a certain amount of attention from this group. This has primarily been for the purpose of either 'proving' or 'disproving' the existence of this act in the initiatory practices of the Isis/Sarapis cult as a parallel to Christian baptism, specifically in it's formulation by Paul Rom. 6.1-11... This material from Apuleius provides us with more than enough evidence to suggest that the connection between baptism, death(symbolic, actual or simply the possibility thereof) and initiation into the cult of Isis would have existed in at least the popular mind... This mosaic is connected with Isis and depicts a scene of the Nile Valley in flood. On it (center, left) is the representation of a temple with what looks much like a bath or, as Witt styles it, 'a kind of baptismal font'. In his rather more full discussion of the archaeology of the 50 or so sites of centralized worship in the Isis and Osiris cult, with specific reference to the water-related facilities, Wild suggests that 'they appear to have a significant function within the cult'. Wild is, however, in some disagreement with Salditt-Trappmann, who suggests that the 'crypt' of the Iseum at Gortyn on Crete was used for actual baptism. While he does not fully share Salditt-Trappmann's extended views on Isiac baptism, he does support this aspect of her interpretaion: 'That individuals entered basins in these crypts'- here referring to the widespread existence of crypts in Graeco-Roman Isea- 'to undergo a ritual drowning appears somewhat...credible. '... It does not seem that Wild has actually inspected the evidence at Gortyn about which he speaks, while Salditt-Trappmann's discussion of the site seems to be based not only on published details of the archaeology of the sites, but also upon first-hand investigation... However, it would appear that he does stray into the realm of 'their nature and meaning' in his theory that the crypts found in many Isea and Serapea were 'places in which [the Nile] flood symbolically but "really" recurred from time to time', which would then 'preserve this sacred water for the need of the cult.' We will have reason to return to Wild's theory later, but first, it seems important that we investigate the role that a baptismal ritual might have played for the individual initiate into the Isiac mysteries. Specifically, the connection between- or identification of- the myths of Isis and Osiris(now Sarapis) and the initiation process. To this question, two tentative answers may be offered. The first is that, as has been suggested in the past, the Isiac initiate, in baptism, identified with the god Osiris, whose death in the Nile was one of the central myths of the Isis cult...The admixture of the various mythologies of the Graeco-Roman period led to a very interesting situation in the discussion of any particular expression of religion. Two writers in particular- Diodorus Siculus, who probably published his Library of History sometime between 36 and 30 BCE, and Plutarch, whose career covered the last half of the first century CE- showed a great deal of interest in the gods, religions and myths of Egypt and their various relationships to the Greek gods, religions and myths. The results of their investigations make very interesting reading, and may offer clues to the content of the central myths of the Isis and Osiris mysteries. As these writers make clear, the identification of Osiris with Dionysus seems to have occupied a great deal of the discussion of the religious and mythical role of Osiris, and we should expect that recourse to the Dionysian mysteries, especially in their later Orphic form, would also be a legitimate avenue of research into the possibility of identification between the initiate into the Isiac mysteries and the dying and rising Osiris... In ancient times, the Osiris myth was the basis for what are perhaps the first mysteries- the lawful succession of the pharaohs, their burial and eventual union with Osiris in the afterlife. This 'mystery' eventually became something in which not only kings but other Egyptians could partake, and, in time, spread across the known world, along with the worship of Isis and Sarapis. For our purposes here, both of these elements separately and in combination suggest that the Isis initiate did indeed go through a process of identification with the god Osiris, and that this fact would have been the assumption behind the entire initiation process. In the first place, the ancient form of the Isis-Osiris mysteries clearly has the kings, and later normal people, identifying with the god Osiris in the hope of unification with him in the afterlife (and even, possibly, in his resurrection). This is indisputable. We have no reason to think that the worship of Isis and Osiris (Sarapis), as it spread throughout the Graeco-Roman world, changed it's essential myth in any great way. The initiate of the first century would surely have partaken in the mysteries akin to those practiced throughout the history of the Isiac cult. This is where the identification of Osiris and Dionysus becomes most important... This would suggest that the myths that we know about Osiris and Isis were indeed aetiological myths for the Isis cult... The most striking texts are those which equate the central Orphic myth with the story of Osiris: Plutarch, Isis and Osiris 364E-365B, 'the tales concerning the Titans and the rites celebrated by night [i.e. the Orphic orgies] agree with the accounts of the dismemberment of Osiris and his revivication and regenesis'(LCL); and Diodorus Siculus 1.25.6-7, "Isis discovered the drug [or 'charm/spell'] of immortality, by means of which she not only raised from the dead her son Horus, who had been the object of plots on the part of the Titans and had been found dead under the water, giving him his soul, but also made him to receive of immortality." The collocation of death, water and resurrection in this last passage makes an extremely strong case for the cultic connection of these elements... Despite the fact that Burkert cites Wild's theory as though it alone will refute the silly notion that baptism took place in the Isis cult (while completely ignoring Salditt-Trapmann's contrary notions), what we know of the role of aetiological myths in Graeco-Roman mystery religions would suggest the opposite interpretation. Given the specific nature of the myth that undergirded the Isiac religion, it would seem more reasonable to suggest that this identification of the crypts as re-enactments of the nile itself would even more strongly lend credence to the idea that such constructs had a role to play in the initiatory process itself, even one in which the initiate descends into the underworld through a re-enactment of the death of Osiris. Rather than give difficulty to the idea of initiatory baptism in the Isis/Serapis cult, Wild's theory with regard to the crypts, when taken in conjunction with many of the other elements presented in this paper, offers some of it's strongest support.
It is not until the reign of Hadrian, that is, in the first half of the second century C.E., that we encounter such a text, and we find ourselves no longer in an Egyptian, but an Egyptianizing, context. But the text is so rich in genuinely Egyptian allusions, and it touches so closely on our theme that it is well worth considering here.
The text in question deals with the initiation of Lucius into the mysteries of Isis, as related by Apuleius in his novel "The Golden Ass.” The scene is not Egypt but Cenchreae, the harbor of Corinth, where there was an Isis sanctuary. In the Hellenistic Isis religion, the goddess embodied her adherents’ hope for eternal life, and she brought a great deal from her Egyptian past to this role. It was she who had awakened Osiris to new life
through the power of her magical spells. And since, according to Egyptian belief, every individual became an Osiris by means of the mortuary rituals, his hope for immortality depended on Isis as well. There is good reason to think that ancient Egyptian burial customs lived on in the Hellenistic Isis mysteries, though in the latter case, they were enacted and interpreted not as a burial of the deceased but as an initiation of the living.
When Lucius, who has been transformed back from an ass into a man, wishes to be initiated into the mysteries of Isis, the priest advises caution:
For the doorbolt of the netherworld and its saving protection lie in the hand
of the goddess, and the ordination itself is celebrated as the reflection of a
voluntary death and a salvation granted upon request. For when a lifetime
is over and men stand on the threshold where light ends, then the goddess
calls back from the netherworld those to whom the great mystery of
religion was confidently entrusted, and she sets those who have in a certain
sense been reborn through their providence once again on the course of a
new life.
Initiation thus clearly had the sense of a prefiguration of death, one that conveyed to the mystic a divine presence that otherwise, according to the Egyptian view of things, was imparted only to the ritually “transfigured” dead. By voluntarily experiencing this symbolic death, the mystic qualified himself to be brought back to life by Isis on the day of his actual death.
When the day of the initiation finally comes, Lucius is first bathed (baptized), and the priest “expresses the forgiveness of the gods.” The bath thus has the sacramental sense of a remission of sins.
Lucius is initiated into the mysteries of the netherworld. He carries out the descensus of the sun god, descending into the netherworld and beholding the sun at midnight. With these sentences, we cannot help but think of the Books of the Netherworld that are to be found on the walls of the Ramesside royal tombs and in the Osireion at Abydos. 56 We may imagine that the mystic was led into similarly decorated rooms — perhaps thecrypts — of a temple. In any case, the process seems to be a symbolic journey through the netherworld, in which the netherworld is depicted, in an entirely Egyptian sense, as the subterranean realm of the midnight sun.