Days ago, slimboy screenshot an excerpt from a book discussing the evolution of the messiah concept. That book and many others have demonstrated, very convincingly, that among the diverse sects of Hellenized Judaism a matrix of pre-Christian concepts gelled into Christianity. The 'Two Powers' theology, "The Great Angel", Holy Spirit, Wisdom, Shekhinah, Light, Logos and Son of God, Son of Man, concepts all occur or were understood as embodied emanations of God during second temple Judaism. Substitutes for God as it were. When the first Christians 'perceived' from these texts and 'visions' an invisible drama of the Christ descending from the highest regions of heaven and being hung on a tree by wicked spirits, their seemingly foreign ideas were actually a natural extension of a sophisticated Jewish ideation of God and Messianism. Given the diversity of Judaism and Hellenism that inspired Christianity, it would seem unrealistic to insist upon a singular picture of 'original' Christianity. In this model of Christian origins, we begin with broad strokes of belief in divine salvation through an invisible emissary of God.
As I've expressed before, it appears certain second/third generation Christians adapted Old testament narratives to dramatize the invisible. They freely drew from the OT, hundreds of story and prophetic elements to 'flesh out' what was understood as spirit. I suspect that the original form of Mark was a didactic play for recruitment or instruction. Christ was given a name, Emmanuel and Joshuah, his father was Joseph, the towns he lived in were Bethlehem and Nazareth, he walked the exact routes of OT figures, he sat at the same well, he performed the OT miracles, all drawn from the OT and related writings. The popularity of this dramatization unfortunately led to literalization. Christianity was transformed via euhemerism. What was once an esoteric faith in the divine formed through visionary interpretation was overlain with a cult of a literary person killed by Romans. The Church Fathers and others created a hybrid of the two. They were intellectually attracted to the higher Christology of the original but leaned on the literalizations as a defense. The same continues today.
Is it any wonder debates about the nature of this Christ have continued for 2000 years? The modern selection of texts used for these debates were chosen by Church Fathers and later leaders to permit both a fully divine Christ and a fully human Joshua.