The sense of Jesus family tree

In the begining the jews presented Jesus, the son of of carpenter called Josephus,
as a descendent of King David,
so that he may fit in the "prophecy" from 1.Chronicles 17:11-14 
and so there were created family trees, pretending with no evidence that Jesus would be a descendent of King David as presented in 
"according Matthew" 1:1-17 and "according Luca" 3:23-38.

In this way Jesus was announced as the future king of the jews and
as the kings were anointed in an appropriate ceremony as kings,
they were called Messia, anointed kings (in greek Christos).

In this way Jesus was advertised as the future Messia (anointed King of the Jews).
The problem is that Jesus was hanged, see Babylonian Talmud Tractat Sanhedrin 43a of rabi schools (mișna)
and Jesus was never anointed as King of the Jews, and so he cannot be called Messia (Christos).

Still this ideas were catched up by the later christians and Jesus was further incorrect presented as "The King of the Jews" and accordingly falsely named Meslia (Christos),
and his follower were falsely designated as Christans (from Christ).

The different christian sect created different types of Jesus. In the begining Jesus was advertised as not beeing killed by the Jews,  as the holy Irenaeus wrote
in his book Against Heresys Chapter XXII:
"The thirty Æons are not typified by the fact that Christ was baptized in His thirtieth year: He did not suffer in the twelfth month after His baptism, but was more than fifty years old when He died.
... but from the fortieth and fiftieth year a man begins to decline towards old age, which our Lord possessed while He still fulfilled the office of a Teacher, even as the Gospel and all the elders testify; those who were conversant in Asia with John, the disciple of the Lord, [affirming] that John conveyed to them that information.3141 And he remained among them up to the times of Trajan." 
Quelle: https://www.ccel.org/ccel/schaff/anf01.ix.iii.xxiii.html

The agnostic christians from the second half of the second century (christian counting) created another Jesus, which was born by "virgin" Mary to whom her husband Joseph never had intercourse than she was inseminated by a special ghost, called "the holy ghost" caming from Jehova.

But if this was the original story, than it would make no sense create family trees for Jesus, where he is presented as the son of Josepht, through whom he would be 
- a descendent of king David 
- and thus as the future king of the jews as presented in 1.Cronici 17:11-14

In the creation of the new Jesus, the helenistic cristians, have been inspired by the greek and egiptian literature about the 
  - virgin creation
  - and the deific nature of the new born king
 see Isus copiat după Horus.