His account of the birth of Jesus in Luke 2 is rooted in history, in time and place, and people. If Theophilus or any other hearer/reader wanted to get on their horse or donkey and go to where Jesus was born, they could. They would undoubtedly meet some who knew of the events. Members of Jesus' earthly family were still around and could be approached and questioned about what Luke had written.
Today, much scholarly work has gone into determining the truth of the 'historical' Jesus, and the evidence is compelling that Jesus of Nazareth was a real person who lived, taught and moved around Palestine in the early first century - and was crucified by the Romans around AD 33. Such scholars, Christian and non-christian, agree that there is a "Jesus-shaped bump" in history since that time. It is a ripple that has become a global tsunami of the Christian movement.
We believe Jesus was so much more than "just" a historical figure. We follow Jesus because He is so much more, and not just because of what He taught and did, but because He is risen and has overcome the grave, He has ascended and will return.
Peter wrote of his experience, and that of his friends James and John, on the mount of Transfiguration. "We did not follow cleverly designed stories" he wrote to the persecuted Church. "We were eyewitnesses to His majestic glory..", "we heard the voice of God in the cloud...", and "we have this prophetic message for you, the Church, to pass on..."
The Church does not worship or follow an historical figure, but the living Lord Jesus who reigns over all creation.
We worship Him because He is full of grace and truth. In an age of information, knowledge is a valuable treasure.
Luke's Gospel provides knowledge about who Jesus was - and in the sequel "The Acts of the Apostles" Luke provides knowledge about who Jesus is.
If you want to know who Jesus was, and is, read through the Gospel of Luke. Even if you don't believe, at least you can seek to understand. It's better than relying on "information" that could be as useless as it is abundant.