Christian apologetics amounts to offering a defense for what Christians believe. Not surprisingly, there are different approaches to the practice of Christian apologetics. One of the most common approaches is known as presuppositional apologetics, and this is what will interest us here.
Presuppositional apologetics – What is it?
Presuppositional apologetics holds to the belief that Christian apologetics (or any other kind of apologetics, for that matter) must begin with a set of presuppositions, that is, beliefs which are taken for granted from the outset. For the Christian apologist, this means that the biblical teachings about God and Jesus (as well as the rest of the Bible) are taken to be given as true from the outset. The apologist then proceeds to make a defense for the Christian faith by showing that these biblical presuppositions allow one to make better sense of the world than other, non-biblical presuppositions. In this sense, the presuppositional approach differs significantly from the classical and evidential approaches to Christian apologetics, which take a more "first principles" approach to demonstrating the superiority of Christian faith. Another way of saying this would be that, whereas classical and evidential apologetics focus on demonstrating the truth of Christianity, presuppositional apologetics focuses on demonstrating the internal consistency of Christianity. And of course, all three approaches do ultimately encourage belief in orthodox Christian teaching.
To better appreciate this distinction between classical/evidential apologetics and presuppositional apologetics, consider the analogy of buying your friend a new shirt. One possibility would be to take your friend to a local tailor, have them sized up and measured in every possible way, and then have a shirt made to fit them exactly. Another possibility would be to take your friend to a local clothing store, and to have them try on shirts one at a time, until they find the one which fits them. The first possibility is similar to the classical/evidential approach, because it constructs the "shirt" (i.e., system of beliefs) by starting directly with basic principles of reasoning and the evidence for the Christian faith. By contrast, the presuppositional approach is similar to the second way of finding a shirt, because it essentially encourages the unbeliever to "try on" the Christian worldview, and shows that it "fits" better than any other worldview.
This analogy is potentially unhelpful in one important respect, in that it can certainly be carried too far. It's important to realize that truth is completely objective; we do not get to choose a belief system simply to suit our tastes, as we would if we were choosing a shirt. While different shirts fit different people best, Christianity is objectively true, meaning that it is "one size fits all." The presuppositional approach to apologetics does not imply that Christianity is only suitable for those whom it "fits," as a shirt would be; it only holds that the most effective way to help a person see the superiority of the Christian worldview is by helping them to "try it on for size," thereby revealing that it makes the best sense of the world we live in.
Having discussed what presuppositional apologetics is, we can still ask whether we see examples of this apologetic style in Scripture. In fact, we do: for example, in Acts 17, the apostle Paul appeals to the Greek unbelievers in his audience, acknowledging both their deep religiosity (Acts 17:22) and their innate sense of morality and moral accountability (Acts 17:30), things which can only be grounded meaningfully in a biblical worldview. In this case, Paul does not attempt to prove every statement that he makes, but rather chooses to present the full gospel in a succinct and cohesive manner, allowing the Spirit of God to work through his presentation to turn the hearts of whomever He pleased. By inviting his Greek audience to "try on" the Christian worldview in this way, Paul is engaging in a kind of presuppositional apologetics. And indeed, in this case, Paul certainly did reap a harvest for the kingdom of God (Acts 17:32–34). So the presuppositional approach certainly appears to have biblical precedent, and can clearly be an effective method for sharing the gospel.
What is Christian apologetics and why is it important?
Classical apologetics – What is it?
Evidential apologetics – What is it?
Can the existence of God be proven?
Are Christians supposed to defend the faith?
Truth about Worldview and Apologetics