At some point we all hit the upper end of our capacity to
effectively persuade others with dialectical arguments. Education, IQ, maturity, grasp of relevant facts, logical mindset, time spent in the word of God and life experience are all “ceilings” of a sort. Limitations in these areas, understandable or otherwise, create a barrier beyond which we become significantly less persuasive when we try to make the case for
the gospel to people on the higher end of each spectrum.
Some of these barriers may be hurdled with sufficient time,
prayer and hard work; others, like IQ, are pretty much hardwired whether we
like it or not.