Now that we’ve understood that we all have unquestioned presuppositions, it’s fundamental to understand how to prove something. Nancy Pearcey formulates this question as « If the starting premises are not based on reasons, how can they be tested? »¹ She goes on to say:

While it’s impossible to go back to previous reasons, it is possible to move forward by stating their implications, then testing them with logic and experience. This is the strategy we’ll follow in the rest of Finding Truth. It will prove remarkably effective, demonstrating that Christianity surpasses all competing worldviews.²

The proof, or the positive result of the test, comes from the answers to these few questions: is it logical and coherent? Is it consistent with reality? Pearcey breaks these questions down into criteria or principles for evaluating a worldview. For Pearcey, for something to be considered true or proven, it must not be reductive, and it must be consistent within itself and with reality.

Interestingly, Schaeffer uses almost the same language when talking about evidence. In his book The God who is There, he seeks to show the rational character of the Christian faith. That’s why it’s important for him to define what evidence is:

Whatever the problem to be solved, whether it’s a chemical reaction or the meaning of mankind, there are two stages in the administration of proof: A. The theory must be coherent and provide an explanation for the phenomenon under consideration. B. It must be consistent with reality. For example, the explanation proposed for a chemical reaction must correspond to what is observed in the test tube. As far as man and his humanity are concerned, the solution must be in line with what a wide-ranging examination of human beings and their behavior reveals.³

Christian apologetics, in this case, has to make clear everyone’s questions about the Christian faith, show the coherence of the biblical worldview, show the solution it proposes and, finally, show that it conforms to reality and is therefore viable. This last part is done by living the gospel around us and showing what the Christian life looks like in a practical way.

1. N. PEARCEY, Finding Truth: 5 Principles for Unmasking Atheism, Secularism, and Other God Substitutes, David Cook, Colorado Springs, 2015, p. 63. ↩︎
2. Ibid ↩︎
3. F. SCHAEFFER, Dieu illusion ou réalité ?, Éditions Kerygma, Aix-en-Provence, 1989, p. 96 ↩︎