- I Corinthians 1:21, 2:4-5, II Corinthians 4:3-4, I Corinthians 2:14
The classical apologetics approach is to memorize lots of facts: biblical manuscripts, archeology, evolution, etc. These facts are intended to answer every conceivable objection that an unbeliever might have. It is based on an assumption that unbelief is a matter of ignorance, and that enough facts will convince the unbeliever to become a believer.
The problem is that there is no such indication in Scripture. When we read the Book of Acts, what answer do the evangelists give to their audiences? A list of facts, an expectation that there is a common ground from which an unbeliever can be led to belief? Not even once. Rather, the Apostles always answered with Scripture.
In the verse I quote above from the two epistles to the Corinthians, what does Paul tell us about the process of apologetics? He tells us that God didn't choose bald facts as the means to convert the unbeliever. Rather, He chose the folly of preaching (see also Romans 10:13-21). That's because belief doesn't come from an exercise of intellect. Unbelievers already know about God (Romans 1:18). Paul made that same point when he pointed out the altar to "the unknown god" in Athens (Acts 17:23). The problem isn't a lack of information, but rather that they hate God and the knowledge that they are answerable to Him. The problem for the unbeliever isn't ignorance but unbelief (Romans 8:7)!
What is the nature of the unbeliever that is addressed by the apologist? It is that Satan has blinded him, not to knowledge, but to consequences. It is only the Holy Spirit, not a list of facts, that can tear away that willful blindness, because spiritual truth isn't understood as bald facts, but as a spiritual revelation.