It is asserted here (and here) that Luke wrote to Theophilus the high priest of 37-41CE. I have wondered for years what this Theophilus would have known, assumed, and recognized in Luke's writings. How many of Luke's named characters would Theophilus have known, either personally or by reputation? What events would Theophilus have understood as particularly significant?
Theophilus' family members included two high priests significant to Luke's Jesus story: Annas (father) and Caiaphas (brother-in-law), listed in Luke 3.2. Archaeological evidence links a Johanna to Theophilus the high priest. Luke mentions Johanna in 8.3; 24.10. Most probably, Theophilus would have known (of) Zechariah the priest, who served in the temple in the days of Herod (1.5, 8, 9), and who is mentioned by Luke in 3.2 following Annas and Caiaphas. He probably knew much concerning Zechariah's son, John. John, having been put to death by Herod (3.19-20; cf. Matt 14.6-12), would have been a familiar subject to both Theophilus and Johanna, who married Herod's steward, Chuza (8.3).
Now concerning John:
For some reason, it is a popular position in NT scholarship to assert that John was NOT associated with the Qumran sect. The reasoning generally rests upon the lack of any explicit reference to John's association with Qumran, and any lack of specific location for John's wilderness and Jordan ventures. But, what if this reasoning is incorrect? We know from the Dead Sea scrolls that Qumran was a counter-temple sect: the people retreated into the wilderness because they thought the priesthood was corrupt. If Luke were to describe anyone coming from the south Jordan region doing and preaching things similar to what we find in the scrolls, then would it have been necessary to explicitly say that individual was from the Qumran sect, especially considering the recipient, Theophilus, was a member of the temple establishment and would have been most familiar with counter-temple movements such as Qumran?
Aside from his close proximity to Qumran, there are other elements to John's life which indicate that he would have been considered a temple defiant. His baptism was of repentance and for the remission of sins. These ethical standards were sanctioned by the temple establishment, not individual radicals in the countryside and wilderness. These were temple rituals, performed by the priesthood. John's declaration that a person was free from sin because of his baptism in the Jordan river would have been seen as counter-temple to any first century Jew. Theophilus would have recognized these details in Luke's story.
Now concerning Jesus:
Since John was Jesus' forerunner, it follows that Jesus was probably most interested in John's agenda. And since John is portrayed as a temple-defiant, might the same be true of Jesus? Luke cites Isaiah 40.3-5, a favorite Qumran text, to describe John, the one "preparing the way" for Jesus (Luke 3.4-6). Jesus likewise cited Isaiah to describe his own ministry (Isaiah 58.6; 60.1-2 in Luke 4.18-19). And Jesus contrasted John with those who are "beautifully adorned in palaces" (Luke 7.25), an adequate description of the priesthood. (It might also be that Luke is contrasting John's ministry with that of the priesthood in 3.2ff.) Jesus' acceptance of John's ministry as a contrasting or competitive effort was widely known. He even employed some of John's language in his own preaching (compare, for example, Luke 3.7ff. [and Matthew 3.7ff.] with Matthew 12.33; 23.33).
Jesus himself behaved like a counter-temple movement. Luke 4.1ff. tells of Jesus' retreat from the Jordan into the wilderness, the wilderness region previously identified with John, being the starting point for his own ministry, and to which he returned at times (5.16). By saying that Jesus was "led away by the Holy Spirit...into the wilderness", perhaps Luke is suggesting that it was divinely intended or authorized that Jesus became identified with (and eventually assumed for himself the role of) a counter-temple movement. Jesus forgave sins (Luke 5.21-24; 7.36-50; 15.11-32; 23.40-43). (Interestingly, in 5.21-24 Jesus links his authority [ezousian] to forgive sins with his being the Son of Man - a trait possibly linked to the one like a son of man in Daniel 7.13-14 [LXX], who is given dominion [ezousia]. Crispin Flether-Louis has argued successfully that Daniel 7 is a high priestly text, and that Jesus interpreted it for himself with this in mind.) On occasion, after having healed someone, Jesus sent that one to present him-/herself to the priests. While it might be suggested that Jesus was simply obeying the Law of Moses in sending those healed to the temple, most probably Jesus was demonstrating that what was previously sanctioned by the priesthood (confirming healings) had been transferred to him. Two details of Luke 5.12-15 help exemplify this: 1) Jesus assumed that the rite detailed in the Law remained legitimate (see Leviticus 13.2-17, 49; 14.2-9). 2) Jesus desired to "prove to them" (the priests) that his work was legitimate. He did what priests did, and therefore was in no need of the temple priesthood. His work was sanctioned by God. The temple needed cleansing (Luke 19.45-46), and Jesus predicted its destruction (21.5-6). He was, in essense, counter-temple.
Theophilus the high priest of 37-41CE would have recognized all of this immediately upon reading it. This is why Luke mentions these details - to give his Jesus story a force only a high priest could appreciate.