The first four verses of Luke set up some expectations for the Gospel. Luke tells us he cares about history and evidence, uses posh Greek words some used by historians (especially Jewish history), yet by naming Theophilus and his use of the first person (I) he also sends other signals. This is history but personal, Greek, but embedded in Judaism and especially Scripture.
Then the chapter continues with a string of echoes of the Old Testament Scriptures. Jesus birth grows out of the Old Testament the way plants grow out of the soil not as something strange and new, but as something recognised yet changed, new and wonderful, yet familiar.