A critical part of Christians effectively engaging the culture is something called apologetics, which simply means defending the veracity of the gospel and Christian worldview. The term comes from I Peter 3:15:
But in your hearts set apart Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have.
The Greek word for “to give an answer,” or sometimes translated as a defense is ἀπολογίαν, apologia. Thus the term apologetics. We cannot be effective witnesses for Christ in the culture unless we know what we believe, i.e. theology and doctrine, and why we believe what we believe, and are able to effectively, and winsomely, defend it.
One of the reasons Christians can have confidence in what they believe is that we can be reasonably certain that what we read in our New Testaments is what was actually written by who it was written by. Even when they disagree with the who part, non-believing scholars agree that the text of the New Testament we have comes to us pretty much accurately from the first century. We know this because of a science called textual criticism, which simply means how we handle ancient texts to get as close as possible to the original manuscripts, in our case what was actually written by Matthew, Mark, Luke, John, Paul, et al.
As new discoveries have been made over the last century the case for the validity of the New Testament text has only grown stronger. Now we have an exciting new discovery that has given us the oldest copy of a gospel text known to exist. This fragment from the gospel of Mark, the earliest written of the four, has been dated to before 90 AD. The implications for our faith are too deep to go into in a blog post, but they are multifaceted and encouraging. You can find out more at this book review of Craig Blomberg’s The Historical Reliability of the Gospels, and if you’re so inclined read the book. It’s on my Wish List.