The fool proto-catholic apologist Irenaeus informs us that the Earliest Gospel was written against who exalted the figure of Jesus the Son of Father and (in parallel) despised the Jewish Messiah (in Greek, Christ):
Those, again, who separate Jesus from Christ, alleging that Christ [=the Jewish Christ] remained impassible, but that it was Jesus who suffered, preferring the Gospel by Mark, if they read it with a love of truth, may have their errors rectified.
http://www.newadvent.org/fathers/0103311.htm
Here I find the explanation (in bold):
But who is the Saviour Jesus now identified with the god revealed in the Old Testament? He is, as the Emmaus narrative suggests, the instructor serpent of Paradise. The saviour serpent is venerated as such and identified with Jesus by the gnostic sects enumerated in Book V of the Elenchos, in particular by the Naassenes (from the Hebrew naash, serpent). According to the Sethians, the serpent is the perfect Word of the Light from above (=of the supreme god). According to the gnostics of whom Irenaeus wrote, Eve believed what the serpent said as easily as if she had heard the Son of God. Jesus himself in the Apocryphon of John (BG 57,20) declared it was he who had incited Eve to eat the fruit. Mani, according to Theodorus Bar Khonai, will say that Jesus the luminous came to Adam and roused him from a deathlike sleep, that Adam knew who he was, enslaved in the stench of Darkness. The Ophites (from the Greek ophis, snake), according to Epiphanius (Pan. 37) celebrated the Eucharist by breaking and distributing loaves of bread around which a living serpent was coiled, which makes this Eucharist, like that of Emmaus, into a substitute from the fruit of Paradise. The serpent, the Peratae said, appeared in human form during Herod's reign…
The divine being formerly hidden behind the serpent had to manifest itself as a human being so that he could be attributed with the revelations and saving instructions which his disciples transmitted as logia ('Jesus said...'), and with the institution (at the Feeding narrative) of the sacrament of the Eucharist as a substitute for the fruit of Paradise.
To make the Jews accept this saviour, he had to be identified with one of those men mentioned in the Scriptures, whose coming they awaited. Jesus will be a prophet like Moses and the 'messiah' promised by Daniel. And to make the gnostic saviour coincide with the Jewish messiah, both of them had to be redefined: the former will become true man, the latter will become true god. It is towards this conciliation that the Evangelists will work by giving Jesus a simili-biography. The function of the Emmaus narrative, for example, will be to affirm that the heavenly crucifixion of the saviour by the Archons — terminating the reing of astral fatality and alluded to in 1 Co 2:8 —, transposed into a Roman-style crucifixion 'by the archpriests and archons', was predicted of the messiah.
So the serpent effects a double exchange of identity with the Jewish god: firstly, with its negative aspect, as the Jewish god, who has become the devil, is identified with him; secondly, with its positive aspect, as the saviour, who was concealed in the serpent, becomes the Lord Sabaoth. The saviour Jesus is, furthermore, both the Jewish god and his messiah, who has become the messiah of the Father: Christ. He will be called Jesus Christ.
The divine being formerly hidden behind the serpent had to manifest itself as a human being so that he could be attributed with the revelations and saving instructions which his disciples transmitted as logia ('Jesus said...'), and with the institution (at the Feeding narrative) of the sacrament of the Eucharist as a substitute for the fruit of Paradise.
To make the Jews accept this saviour, he had to be identified with one of those men mentioned in the Scriptures, whose coming they awaited. Jesus will be a prophet like Moses and the 'messiah' promised by Daniel. And to make the gnostic saviour coincide with the Jewish messiah, both of them had to be redefined: the former will become true man, the latter will become true god. It is towards this conciliation that the Evangelists will work by giving Jesus a simili-biography. The function of the Emmaus narrative, for example, will be to affirm that the heavenly crucifixion of the saviour by the Archons — terminating the reing of astral fatality and alluded to in 1 Co 2:8 —, transposed into a Roman-style crucifixion 'by the archpriests and archons', was predicted of the messiah.
So the serpent effects a double exchange of identity with the Jewish god: firstly, with its negative aspect, as the Jewish god, who has become the devil, is identified with him; secondly, with its positive aspect, as the saviour, who was concealed in the serpent, becomes the Lord Sabaoth. The saviour Jesus is, furthermore, both the Jewish god and his messiah, who has become the messiah of the Father: Christ. He will be called Jesus Christ.
(Jean Magne, From Christianity to Gnosis and from Gnosis to Christianity, p.68-69, Brown Judaic Studies 286, my bold)
