In chapter two, The Biblical Basis for Apologetics, Groothuis states that “the task in this chapter is to tighten up our understanding of apologetics by explaining its basis in Scripture.”

Christian apologetics is the rational defense of the Christian worldview as objectively true, rationally compelling, and existentially or subjectively engaging. The word apologetics comes from the Greek word apologia…. In the days of the NT “an apologia was a formal courtroom defense of something (2 Timothy 4:16) …. The term is used specifically for a rational defense of the gospel in three texts: Philippians 1:7, 16, and most famously in 1 Peter 3:15-16.”