In Acts 26:24, during Paul’s defense, he is cut off by Festus, who really can’t take anymore religious talk. Why? The teaching of a suffering king who died ,then rose from the dead and appeared to Paul, is folly to a Gentile, such as Festus (1 Cor. 1:23). So he accuses Paul of being insane and links this madness to his great learning—“You studied so much, you’ve got a couple screws loose Paul.” This is a common response when you ask an unbeliever to consider the unseen, spiritual realm. Why does this happen? Because an unbeliever lives for what he feels and what he sees and what makes sense to his natural mind. Thus, he only makes calculated decisions about what will bring him immediate, tangible benefit. That’s why many in our time often say things like this: “You’re crazy for thinking the Bible is God’s word—don’t you know that man wrote it and that’s it’s full of scientific and historical errors? You’ve abandoned all your rational abilities if you believe God created this world in 6 days out of nothing. How do you know for sure Jesus even rose from the dead? There aren’t any eye-witnesses living today and he hasn’t shown himself for over 2,000 years. None of that matters anyways because the Bible is full of many contradictions to science.”
These are not surprising responses because the Bible teaches that the natural man is depraved in his heart and thus deprived of spiritual insight. Accordingly, Eph. 4:18 teaches that the unbeliever is darkened in his understanding and thus unable to connect spiritual dots. Notice Paul’s response to this accusation in v.25—an insane person does not boldly declare true and rational words. They are true because they line up with Scripture, which is the only way to determine truth from error with regards to spiritual things. They are rational because they involve sound arguments and not senseless babbling. Think about this—even the consistent hostile response Paul received throughout his ministry proves he was making sense.
How could entire cities become enraged at an insane person? Paul’s opponents weren’t upset because they thought he was insane; rather they were furious precisely because they knew exactly what he was saying about their lives and they refused to give up their idolatry or self-righteousness.
The point is that Christianity is not irrational, but it is absolutely unacceptable to those who love their sin and love worshiping themselves and their own intellect. This is so crucial to keep in mind when we are dealing with those who are hostile to the truth and/or those who refuse to believe. Yes, perhaps we can become more clear in our articulation of gospel truths and even more direct in our statements about how the truth confronts the sin of mankind, but ultimately the issue is not rational comprehension. Rather, there is a massive spiritual disconnect in all who do not believe and only the gospel can open eyes and connect those dots.