Luke 1:1-25

Luke's Gospel begins with a reference to fulfilment. It is very difficult to think of anything as fulfilled today. The world is so constantly changing and the pace of change appears to be accelerating. If I look at my own life - I hope I am not completed yet - I had hoped for more yet!!
But Luke is talking of a different kind of fulfilment. The sort of fulfilment that marks the end of something looked for, something expected and the arrival of something new.
The account of Zechariah's and Elizabeth is therefore written to ensure that references to what was expected and is now fulfilled cannot be missed - at least not by those who have come to understand.
The events of John the Baptist and Jesus' birth are not isolated events. They are part of vast train of events going right back to Abraham, indeed right back to God's creative act in man (as will be shown in the genealogy of Luke in Chapter 3). So the events that precursor Jesus ministry itself are passed on in the same tradition. Zechariah and Elizabeth, faithful yet childless, continue the story from Abraham and Sarah and from Elkanah and Hanah.
The angel Gabriel - the eschatological messenger of Daniel, bring the message to Zechariah and it will be 70 weeks until Jesus is presented at the temple, fulfilling the language and expectation of Daniel.
John, the child of Zechariah, will be a prophet with a mission to preach repentance, to turn Israel back to God in preparation for the coming of the Messiah - this in keeping with the prophetic expectation of Micah - one like Elijah will come.
As Luke pieces all these things together, you can almost feel his heart burning (like those on the road to Emmaus in Luke 24:32) within him as he writes of the fulfilment of the prophetic expectations of Scripture.
Here 2,000 years on Luke has achieved his undertaking when our hearts burn too. Many people who are not familiar with the Bible and live in the context of society saturated with media may wonder why people get so excited about it. The answer is here. It is not a rule book (although there is plenty of wisdom to be found) it is the revelation of God as to the purpose and destiny of humanity and testimony to the fulfilment of his plans in Christ.
That all will come to fruition (as Morpheus form the Matrix would put it) is not a matter of faith it is only a matter of time.