"if Christ is a symbol of the totality of the spiritual self in everyone then what would be the purpose of creating a literalized external Christ figure, how could that be purposed?"
I suspect that it was the author's purpose to create a 'historical fictional' Christ as sort of a 'carrier' of modulated, philosophical information.
A good modern day analogy is the transmission and reception of a radio signal. Consider the following 'block diagram'.
1) An electronic circuit generates a frequency at 101.1 Khz called ‘The Carrier’.
2) A person with information speaks into a microphone which generates low variable frequencies around 500 Hz called “The Modulator”.
3) The Carrier and Modulator enter simultaneously into another circuit and combine to form a composite signal called ‘THE SIGNAL'.
4) The SIGNAL is amplified and broadcasted via an antenna to the World. Preferrably a wireloop antenna : )
1) Somebody in the world has an antenna which is 'struck by' the SIGNAL.
2) The 101.1 KHz SIGNAL enters a circuit which interprets THE SIGNAL and separates the The Carrier from The Modulator.
3) The 500 Hz Modulator is amplified and sent to the speakers for audibility.
4) The 101.1 KHz Carrier is discarded.
Historical Fictional Jesus = Carrier
Christ Allegory = Modulator
How do you read The Bible?
Tune to it's carrier frequency (Historical fictional Jesus) looking for a SIGNAL.
Seperate THE SIGNAL and amplify only the modulator (Soul allegory).
Discard the carrier (the tutor of literalism) and listen to the sender's information.
Something like that.