“Being confident of these things, a truly Reformed apologetic must begin from the presupposition that the living and true, triune God speaks to him with absolute authority in infallible Scripture. His reasoning then finds its only legitimate function as a servant or tool of God’s word, rather than its judge. Following God’s Word, the Christian receptively reconstructs the created facts of the universe about him with a view toward both fulfilling the cultural mandate and being conformed to the image of his Savior by the power of Christ’s Spirit; hereby he glorifies God and enjoys Him forever. Thus, the apologetic task will consist, not of externally verifying the Christian presupposition but, of applying it by (1) bringing God’s truth and command to bear upon the lives of unbelievers, appealing to the image of God in them (distinguishing between present remnants of man’s orignal nature and the ever-present nature of fallen man), pointing out that every fact of the world bears witness to God, and (2) doing an internal critique of the non-Christian’s system, calling down its idols, and pointing out the absolute necessity of Christian presuppositions if logic, factuality, history, science, and morality are to have any meaning, validity, and application at all. The Christian apologetic will not concede intellectual ground to Christianity’s cultured despisers or allow them to exploit theorethical foundations to which they have no legitimate claim without depending on the Christian faith. Thus, part of the Christian’s reasoned defense of the faith will be an aggressive offense.
Not like the fool who built his house upon the sand, the Christian apologist must, in love for Christ, found his whole life, including apologetical reasoning, upon the solid rock of Christ’s Word. In accordance with this the apologist seeks the repentance of the sinner and does not encourage his continued use of hostile, autonomous reason in judgment over God’s Word. We seek a God-controlled man, not a man-controlled God."
(Greg Bahnsen, Presuppositional Apologetics, Page 6-7)