I think Ascension of Isaiah tells something like the oldest version of the story:
https://www.earlychristianwritings.com/ ... nsion.html
12. And he said unto me: "Crowns and thrones of glory they do not receive, till the Beloved will descent in the form in which you will see Him descent [will descent, I say] into the world in the last days the Lord, who will be called Christ.
13. Nevertheless they see and know whose will be thrones, and whose the crowns when He has descended and been made in your form, and they will think that He is flesh and is a man.
14. And the god of that world will stretch forth his hand against the Son, and they will crucify Him on a tree, and will slay Him not knowing who He is.
15. And thus His descent, as you will see, will be hidden even from the heavens, so that it will not be known who He is.
16. And when He hath plundered the angel of death, He will ascend on the third day, [and he will remain in that world five hundred and forty-five days].
17. And then many of the righteous will ascend with Him, whose spirits do not receive their garments till the Lord Christ ascend and they ascend with Him.
17. And so I saw my Lord go forth from the seventh heaven into the sixth heaven.
18. And the angel who conducted me [from this world was with me and] said unto me: "Understand, Isaiah, and see the transformation and descent of the Lord will appear."
19. And I saw, and when the angels saw Him, thereupon those in the sixth heaven praised and lauded Him; for He had not been transformed after the shape of the angels there, and they praised Him and I also praised with them.
20. And I saw when He descended into the fifth heaven, that in the fifth heaven He made Himself like unto the form of the angels there, and they did not praise Him (nor worship Him); for His form was like unto theirs.
21. And then He descended into the forth heaven, and made Himself like unto the form of the angels there.
22. And when they saw Him, they did not praise or laud Him; for His form was like unto their form.
23. And again I saw when He descended into the third heaven, and He made Himself like unto the form of the angels in the third heaven.
24. And those who kept the gate of the (third) heaven demanded the password, and the Lord gave (it) to them in order that He should not be recognized. And when they saw Him, they did not praise or laud Him; for His form was like unto their form.
25. And again I saw when He descended into the second heaven, and again He gave the password there; those who kept the gate proceeded to demand and the Lord to give.
26. And I saw when He made Himself like unto the form of the angels in the second heaven, and they saw Him and they did not praise Him; for His form was like unto their form.
27. And again I saw when He descended into the first heaven, and there also He gave the password to those who kept the gate, and He made Himself like unto the form of the angels who were on the left of that throne, and they neither praised nor lauded Him; for His form was like unto their form.
28. But as for me no one asked me on account of the angel who conducted me.
29. And again He descended into the firmament where dwelleth the ruler of this world, and He gave the password to those on the left, and His form was like theirs, and they did not praise Him there; but they were envying one another and fighting; for here there is a power of evil and envying about trifles.
30. And I saw when He descended and made Himself like unto the angels of the air, and He was like one of them.
31. And He gave no password; for one was plundering and doing violence to another.
And I think whoever wrote the first Gospel that we recognize knew of a story like this and it was the basis of their narrative, in which they described Jesus descending from heaven to take on a disguise, which is why the Gospel of Mark has Jesus trying to hide his identity. And the purpose of Jesus in the original story was to defeat Satan and save the captured souls of the righteous. But later versions of the story transformed the death of Jesus into a sacrifice and when that happened people started to think that Jesus had to be real flesh, not just an "angel in disguise" in order for the sacrifice to be valid, and thus began the movement to perceive Jesus as a "real human being".
Also confusion emerged over who the "god of this world" was. I think this language was present in the earliest Christian literature, BUT that it meant Satan. There are writings from Qumran that call Satan the "Lord of this world", so such a statement is in line with forms of Jewish thought. But it is also to misinterpret as meaning a different god.