Epistemology in its contemporary post-modern ethos is generally believed to be inseparably hinged upon language. This of course ensures a major paradigm shift in the disciplined human conceptions of reality. It has been stated and is widely acknowledged that the Kantian Noumenal barrier has, in this recent shift, been proved to be looming far closer than it was ever previously considered. This new barrier to the world of ‘objective absolutes’ comprises a barrier of semantics and syntax, and calls for a radical restructuring of all the human sciences. There is surely no discipline in the humanities that can claim immunity to this colossal shift in epistemology, and theology (particularly of the Evangelical variety) is no exception to the rule. The impact of post-modern epistemological assumption upon contemporary Evangelicalism presents to those who adhere to this school’s position, a profound challenge. Conservative Christians, who hold to the propositional universality and the objectivity of biblical truth, find in the post-modern ethos little sympathy and no rational justification granted for their ‘metaphysical objectivity’. A major challenge therefore to Evangelical Christianity at the present time is this: Is there, in the light of the challenge of post-modern epistemology, any reasonable justification for continuing to adhere to the evangelical claim that God has spoken in unchanging propositional terms that are universally valid and binding? It would seem that in this regard many evangelicals are feeling pressured. Evidence of the pressure of this challenge can readily be found either in the growing contemporary evangelical tendency towards advocating a more cooperative attitude to the post-modern ethos, or in the reactionary theology of schools of thought like the Spiritual Warfare Movement. The writings of Clive Staples Lewis (1898 – 1963) have been proven effective in the countering of negative challenges to Christian faith for the past sixty years. Lewis, as an apologist, in the opinion of many intellectual searchers, positively and convincingly countered modernistic objections to faith in his own time. Modernistic assumptions prevailed in the Western world in Lewis’ day that tended to discredit a rational belief in the supernatural. Lewis was widely held to be an effective apostle to counter this modernistic scepticism. It is the conviction of the present writer that C. S. Lewis apologetics can be just as effectively utilised today in addressing post-modern challenges, as it was fifty years ago used to answer the questions raised by modernism. Lewis in all of his Christian writings, reveals an underlying epistemology that I believe (because it is based firmly upon Christian orthodoxy), has stood the test of time. The apologetics of C. S. Lewis may serve to answer post-modern challenges just as rationally as it did modernism. In this thesis, Lewis’ underlying epistemology will be examined. This will comprise the first part of my work. The second part of the thesis deals with the post-modern epistemological challenge to Evangelicalism as a world-view. The final part of this thesis consists of a dialogue between the most common post-modern challenges to evangelical thinking, and rationally compelling answers thereto that are found in Lewis’ writings.