Spiral said
Why did both Matthew and Luke (or the real authors of those books, whomever they were) go to such trouble to construct a genealogy that links King David to Jesus while at the same time asserting that Jesus was conceived through immaculate conception?  

I can understand why they would write into their account one story or another, either the David to Jesus genealogy OR the immaculate conception.  But why both?  By including both, didn’t they undermine their argument that Jesus was the Messiah?  

Matthew, who started the virgin birth story, had a problem. His Jewish Christian community would insist on the Messiah being a descendant of David. But the Son of God meme was already firmly established and needed to be a lot more than ‘a righteous man’ or other mundane meaning.  Unless this was taken literally to raise Jesus to as high a level as possible, the ‘crucifixion as sacrifice’ idea would not work.

Paul imported Philo’s Son of God idea to make sense of the Messiah getting killed in the first place, making the murder of Jesus into the sacrifice of all sacrifices. It seems to me that Matthew also imported some ideas from Philo. In his On the Cherubim, Philo comments on God inspiring the conceptions of important people but, since God requires nothing, they are the legitimate offspring of the nominal father. In that same work, nearby in fact, Philo also comments on virgins being the ideal partner of God, but not in the human way of course. (The relevant passages are long, Philo being a wordy guy, so I am not quoting them directly here.)

In short, Philo gives Matthew justification for Jesus being the literal Son of God while still being the legitimate offspring of Joseph and therefore a descendant of David as required. The insistence on virginity would be not just a tie in to Philo but a way of ruling out off-screen hanky-panky. The parthenos ‘prophecy’ was just icing on the cake for those who never read Philo.

My take on it anyway.

It has been quite a few years and I do not currently have a copy but as I recall the theme of Two Powers in Heaven was that the apparent polytheism of Christianity and related Gnosticism was recognized and considered heretical by the Jews as early as the 1^st century. Again if memory serves, the author realized the connection between Philo and Paul and John and did not attribute the quasi-divine Son of God / Logos idea to a common form of Jewish thought. But as I said it has been a long time and I am rather beyond the biblical ‘three score and ten’ so I could be in error.

Regardless, Paul’s Son of God and John’s Logos are so strongly tied to Philo’s ideas at the detail level that it would be very hard to not point to Philo as the source.  Likewise, to not point to Philo as Matthew’s inspiration for his virgin birth meme leaves a big hole in his argument. But invoking the On the Cherubim passage renders it sensible and the perfect solution to the dual parentage problem Matthew faced. I do not see this as possibly arising from any common form of Jewish thought.