Regardless of whether one believes the Apostle Paul was a real person or not, a mythicist who claims that Paul’s Jesus was never human, nor was ever intended to be human, has got problems when they try to deal with some subtle hints Paul gives to Jesus’ humanity.
For instance, in 1 Corinthians:
For the word of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God
Paul also makes reference to the cross in Galatians 6:14
But may it never be that I would boast, except in the cross of our Lord Jesus Christ, through which the world has been crucified to me, and I to the world
If Paul thinks Jesus exists in outer space, what good would a cross be? Isn’t a cross a worldly device, rather than a celestial one?
In the various Gnostic systems (for instance, the Valentinians), there are 3 realms of existence: the Pleroma (a heaven-type place), the Kenoma (right below the Pleroma), and the Cosmos (the place created by Sophia’s offspring, the Demiurge). This matches the Middle Platonist view at the time that reality was made up by Forms, The Supralunar, and The Sublunar.
Because Sophia gave rise to a rift in the Pleroma, a virtual doppelganger of Sophia got created in the Kenoma, and there was a barrier that Sophia was trapped by. This entrapment needed to be remedied, so out of the Aeons in the Pleroma came Jesus the Soter (in other systems, he’s referred to as the Logos [word]) to rescue Sophia.
What was the barrier called which trapped Sophia’s doppelganger in the Kenoma?
The Horos. The Stauros. The Cross.
The different Gnostic systems have different reasons and manifestations of and for Jesus, but Jesus’ interaction in the cosmos (beneath the Kenoma and Pleroma) represents a fairly small part of the Gnostic Jesus story.
In any event, the Kenoma is a bit less imperfect than the Cosmos; yet it allows for allegories and metaphors, such as the cross.
To sum up, Paul’s Jesus didn’t live on Earth, nor did (I suspect) any of the other early Christians’ Jesus. The historical Judean Jesus was a later invention which was probably done for a variety of purposes:
1. An earthly Jesus is easier to explain to the uneducated masses
2. Roman persecution made a human Jesus more convenient for a number of reasons (separation from the Jews; a human messiah was more palatable to the Romans)
3. Euhemerization was a typical of the time
4. Various anti-Greek sects preferred the human Jesus (ie Irenaeus)