Elaborate myths of the King Osiris had already developed by 4400 years ago in the Pyramid Texts of Egypt. Myth does not follow logic. It is only in mythology where people become other people where death does not end life and where animals can speak.
Myth itself evolves because it is based on concepts about life not about facts but often the core stories of myth revolve around allegories which never change. For example the God Osiris is murdered by Set the evil one which has its basis in the daily rotation of the Earth when darkness overcomes light. This very simple relationship is an example of what underlies all of the ancient tales; most of them having been drawn from astronomical realities.
Osiris (although dead!) had a son Horus through the virgin birth of his mother Isis Meri. As is possible in myth; Horus existed as different people at different times. Later stories made Horus the same as his father Osiris and perhaps that is why Horus resurrected is other self “his friend” Osiris (Osaris Azarus Lazarus). Horus walked on the water; like his father a sun god, he was seen daily walking on water at sunrise with the double image of two suns, two solar deities, one above the other, the exact image of the other. . .
@Deegee, Horus was with his mother and step father Sep, until twelve years old when he became the son of his heavenly father with no biographic details in the meantime, from twelve to thirty there is no record of Horus. At thirty years old he was baptised by Anup (=John) and symbolically blessed by his heavenly father in the form of a bird.
In answer to the OP. We do have ample evidence of the existence of Jesus outside of the Bible; he is a focal character-- under different names, of supernatural tales which descended from ancient mythology. It was a cheap manoeuvre to swap names but why spoil a good story from another culture!
The Romans never knew of a man who could resurrect the dead; if Jesus really existed they would most surely have recorded the appearance of such a man. However it is so highly unlikely that a figure from fiction could be born and start to breathe, that I would place the Bible’s account of Jesus into the realm of supernatural folk tales.