Apologetics is the theological discipline that defends the truth of the Christian message.
The fear of the Lord is the beginning of knowledge (Prov. 1:7) and wisdom (9:10); indeed, wisdom and knowledge are summed up in Jesus Christ (1 Cor. 1:30, Co. 2:3). Though God is known through his creation, people repress this knowledge (Rom. 1:18-32) until God’s grace renews their minds (Rom. 12:2). The apologist should press upon the non-Christian the evidence that God is clearly revealed in nature. But he should present it in the context of a biblical worldview, with an epistemology reflecting what the Bible says about knowledge. And he should present the Gospel in God’s own authoritative voice, using Scripture’s own arguments (as 1 Cor. 15:1-11) and other arguments that follow scriptural leads. (Source: John Frame Dictionary for the Theological Interpretation of the Bible, "Apologetics")