Luke's gospel tells the story of the life of Jesus from the perspective of Luke, a Greek doctor, who was a traveling companion of Paul (2 Tim 4:11). It is written, as we see in the introduction, so that a man named Theophilus can "have certainty concerning the things that he has been taught".
Remember, they lived in a time where capitulating to the culture would have had a huge payoff since they were being ostracized and sometimes martyred for their faith. There was an overabundance of outside pressure to hide their faith in the name of self-preservation and avoid shame and personal harm.
The Gospel of Luke was to give Theophilus certainty, and I am confident it will give us even more certainty of the things we profess to be true today.