I've been writing about the underlying connection between SGM 1 and the Book of Joshua. I think we can pinpoint the actual 'liturgical day' of this ritual to the tenth day of the first month of the Hebrew calendar (10 Nisan). This was the traditional date that Joshua crossed the Jordan. There are a number of signs in SGM 1 that Mark had this date in mind when writing the narrative. The most convincing bit of evidence I think is that the last line in SGM 1 actually borrows terminology from Joshua 1:15 LXX to illustrate the freshly initiated disciple's journey across the river - εἰς τὸ πέραν τοῦ ιορδάνου ἀπ' ἀνατολῶν ἡλίου.
Not a single one of the leading figures in the recent debate over the authenticity of the Letter to Theodore can claim to be authorities on the writings of Clement of Alexandria. It is worth noting that Clement explicitly references an important and at times 'secret' or mystical 'harmony' between the gospel and the 'prophetic scriptures' (= the Law and Prophets) many times in his writings. I can't help but think that the thing to unravel this whole fragment is the understanding that divine fire came down from heaven (or from within the tabernacle is probably more likely) and literally forced the waters of the river to dry up and go backwards. This actually helps explain the relationship between Secret Mark's description of the initiation and furthermore the subsequent crossing of the Jordan by the initiate.
For I think we have to separate the mystery as taught to the initiate and his experience in the Jordan on the tenth of Nisan and the ritual that was developed in Alexandria around that event. I think Scott Brown is ultimately right - this didn't begin as a water immersion ritual. Indeed Irenaeus tells us as much with respect to the so-called 'redemption' (ἀπολύτρωσις) rite of the followers of Mark:
some of them assert that it is superfluous to bring persons to the water, but mixing oil and water together, they place this mixture on the heads of those who are to be initiated, with the use of some such expressions as we have already mentioned. And this they maintain to be the redemption (ἀπολύτρωσις). They, too, are accustomed to anoint with balsam. Others, however, reject all these practices, and maintain that the mystery of the unspeakable and invisible power ought not to be performed by visible and corruptible creatures ... for since both defect and passion flowed from ignorance, the whole substance of what was thus formed is destroyed by knowledge; and therefore knowledge is the redemption (ἀπολύτρωσις) of the inner man. This, however, is not of a corporeal nature, for the body is corruptible; nor is it animal, since the animal soul is the fruit of a defect, and is, as it were, the abode of the spirit. The redemption (ἀπολύτρωσις) must therefore be of a spiritual nature; for they affirm that the inner and spiritual man is redeemed by means of knowledge, and that they, having acquired the knowledge of all things, stand thenceforth in need of nothing else. This, then, is the true redemption (ἀπολύτρωσις). [AH 1.21.4]
Many scholars read this description and imagine this description and see it as meaning that 'spiritual' baptism is something make believe or imaginary. But the parallel ideas we just cited from Origen's Fourth Homily on the Book of Joshua argues that by 'spiritual' the Alexandrian tradition means 'fire.'
I am now strongly supportive of the idea that the ἀπολύτρωσις was a fire baptism. This comes not only from an analysis of Origen's other writings but also a deeper examination of Irenaeus's description of 'those of Mark' in his Against Heresies. For there is a related work - the so-called Anonymous Treatise on Baptism -which provides some important additional details about the rite. Irenaeus says for instance that the followers of Mark use a great number of passages from the gospel to support the existence of 'another baptism' besides the water immersion ritual. The same arguments are found in the Anonymous Treatise on Baptism. Both sects connect the redemption rite with Mark chapter 10 (and thus perhaps to SGM 1). Indeed the two texts are so very similar in a number of different ways leading me to conclude that the Anonymous Treatise was developed from a lost writing of Irenaeus.
The clincher for me is the claim that both sects which are reported to promote some other kind of baptism are accused of stealing ideas from Anaxilaus of Larissa a physician and Pythagorean philosopher from the turn of the Common Era. According to Eusebius, he was banished from Rome in 28 BC by Augustus on the charge of practicing magic. Anaxilaus wrote about the "magical" properties of minerals, herbs, and other substances and derived drugs, and is cited by Pliny in this regard. His exceptional knowledge of natural science allowed him to produce tricks that were mistaken for magic. As Robert McQueen Grant writes in his Miracle and natural law in Graeco-Roman and early Christian thought
Wellmann has analyzed the examples of magic ascribed to Simon in the Clementine Homilies (ii. 32, iv. 4) and has shown that they are typical of the magical papyri and of the opponents of the satirist Lucian. Simon could make statues walk, could pass through fire without being burned, could fly through the air, could make bread from stones, and so on. Two of Simon's feats are paralleled in the fragments of the Pythagorean magician Anaxilaus, his breaking of iron and his creation of apparitions with all sorts of forms. Did the Simonians know Anaxilaus' book of magical tricks?
The pseudo-Cyprianic treatise [Anonymous Treatise on Baptism] tells us that many people thought that when they made fire appear on the surface of water they were reiving on Anaxilaus. Another gnostic group which employed magic was that which followed the Valentinian Marcus in the second century. They could make mixed wine appear purple and red like blood, and they could also make a large vessel overflow by pouring into it the contents of a smaller one. one. Irenaeus, who describes these practices, says that the Marcosians were combining the "tricks" of Anaxilaus with the craft of magicians. [p 152]
Yet the question that has to be raised by a critical observer is why does Irenaeus identify Mark as a "joining the buffooneries of Anaxilaus to the craftiness of the magi" (AH 1.13.1)? If Anaxilaus was a well known magician the reference to 'magi' clearly is to a Zoroastrian interest in fire.
This interest in magic is confirmed by looking at the description of these heretics in the Anonymous Treatise on Baptism when the author complains of the Catholic baptism rite by saying:
we (have) a mutilated and curtailed baptism, which they are in such wise said to designate, that immediately they have descended into the water, fire at once appears upon the water. Which if it can be effected by any trick, as several tricks of this kind are affirmed to be— of Anaxilaus— whether it is anything natural, by means of which this may happen, or whether they think that they behold this, or whether the work and magical poison of some malignant being can force fire from the water; still they declare such a deceit and artifice to be a perfect baptism, which if faithful men have been forced to receive, there will assuredly be no doubt but that they have lost that which they had. [Anonymous Treatise 14]
Anyone who reads Origen's writings should be aware that he must have been aware of a similar rite in third century Alexandria. Moreover the dispute between the Alexandrian Pope Dionysius and the Roman Pope Xystus over whether members of the Egyptian Church needed to be rebaptized for their original 'heretical' baptism rites surely fits in here too [Eusebius Church History 7:9]
It is enough for us to note that the evidence from the early heretical treatises makes it very likely that 'Simon the Magi' and 'Mark the Magi' were so called for their interest in a fire baptism ritual. Yet I believe what everyone has missed is the fact that this rite must also be one and the same with the sacrament at the heart of the description of the Alexandrian community in to Theodore. I think Origen makes it absolutely explicit in his Fourth Homily on Joshua. He links water immersion with the crossing of the Red Sea and then 'the baptism of fire' with the crossing of the Jordan. I have noticed that the unrepentant 'heretical' tradition associated with Alexandria is always reported to have been involved with 'another baptism' besides water immersion. I am now quite certain that the purpose of the greater Alexandrian mysteries was to immerse (βαπτίζω) the catechumen in fire.
Indeed I also think that we can see hints of this 'secret practice' in various places in the writings of Clement of Alexandria:
But we say that the fire sanctifies not flesh, but sinful souls; meaning not the all-devouring vulgar fire but that of wisdom, which pervades the soul passing through the fire. [Strom 7.6]
But self-control, desirable for its own sake, perfected through knowledge, abiding ever, makes the man lord and master of himself; so that the Gnostic is temperate and passionless, incapable of being dissolved by pleasures and pains, as they say adamant is by fire. [Strom 7.11]
For the Lord says, "He that hath ears to hear, let him hear," declaring that hearing and understanding belong not to all. To the point David writes: "Dark water is in the clouds of the skies. At the gleam before Him the clouds passed, hail and coals of fire;" showing that the holy words are hidden. He intimates that transparent and resplendent to the Gnostics, like the innocuous hail, they are sent down from God; but that they are dark to the multitude, like extinguished coals out of the fire, which, unless kindled and set on fire, will not give forth fire or light. [Strom 6.15]
There are then two things proceeding from the truth, one root lying beneath both, -- the choice being, however, not equal, or rather the difference that is in the choice not being equal. To choose by way of imitation differs, as appears to me, from the choice of him who chooses according to knowledge, as that which is set on fire differs from that which is illuminated. Israel, then, is the light of the likeness which is according to the Scripture. But the image is another thing. [Strom 4.6]
And they (the Basilideans) say that by the words "it is better to marry than to burn" the apostle means this: "Do not cast your soul into the fire, so that you have to endure night and day and go in fear lest you should fall from continence. [Strom 3.1]
Here is to be noted the mystery of the bread, inasmuch as He speaks of it as flesh, and as flesh, consequently, that has risen through fire, as the wheat springs up from decay and germination; and, in truth, it has risen through fire for the joy of the Church, as bread baked. But this will be shown by and by more clearly in the chapter on the resurrection. [Paed 1.6]
The Saviour has many tones of voice, and many methods for the salvation of men; by threatening He admonishes, by upbraiding He converts, by bewailing He pities, by the voice of song He cheers. He spake by the burning bush, for the men of that day needed signs and wonders. He awed men by the fire when He made flame to burst from the pillar of cloud--a token at once of grace and fear: if you obey, there is the light; if you disobey, there is the fire; but. since humanity is nobler than the pillar or the bush, after them the prophets uttered their voice,--the Lord Himself speaking in Isaiah, in Elias,--speaking Himself by the mouth of the prophets. But if thou dost not believe the prophets, but supposest both the men and the fire a myth, the Lord Himself shall speak to thee, "who, being in the form of God, thought it not robbery to be equal with God, but humbled Himself," --He, the merciful God, exerting Himself to save man. And now the Word Himself clearly speaks to thee, Shaming thy unbelief; yea, I say, the Word of God became man, that thou mayest learn from man how man may become God. Is it not then monstrous, my friends, that while God is ceaselessly exhorting us to virtue, we should spurn His kindness and reject salvation? [Exhort 1]
I think there is more than enough here to begin to investigate the possibility that the inherited Joshua narrative might well have provided the basis for this fire ritual. But it is getting late now and I must get some sleep ...