Why is it bad to preach with high-sounding intellectual language?
Preaching with high-sounding, intellectual, perfectly formed statements is bad because people may not know what you are talking about. The Word of God is simple, and the gospel must be laid out plainly so hearers understand what it takes to gain heaven and stand responsible before God.
Les explains that this is what Paul is saying: what good does it do to come in with high-sounding, intellectual, perfectly formed statements if people don't know what you're talking about? The Word of God is simple. Les prays that every time he teaches, he can take these same truths and keep them so simple that a six-year-old can understand. He illustrates this by explaining the gospel to a man in such simple language that the man went away with no doubt about what it would take to gain heaven. The man said he had never heard that before, showing that most people don't. Because it was laid out as plain and simple as it can be, that man will stand responsible someday.