Proverb 26:8 A lying tongue hates those it hurts, and a flattering mouth works ruin.
When we preach we must preach the truth and we must not flatter people. If we focus on expounding the Word then we will be preaching the truth. When we want to use a story for illustration purposes it is important that we do all we can to get the details right and not to tells stories that are untrue. So take stories of thunderbolts hitting churches. That certainly happened but do not assume that the time it is said that it happened and what was being said are correct. Check it out carefully. We have all heard the story of the professor asking a class if they would recommend abortion for a woman with syphillis who already has eight children of whom three are deaf, two blind and one educationally subnormal. They are then told they just killed Beethoven but the details do not fit the facts. Beethoven was the third of eight children his older siblings dying in infancy.
As for flattering people in preaching, it is an important rule of rhetoric to identify with one's audience but we must not flatter them. In Romans 16:18 Paul warns against false teachers saying For such people are not serving our Lord Christ, but their own appetites. By smooth talk and flattery they deceive the minds of naive people. in 1 Thessalonians 2:5 he reminds them how he never used flattery, nor did we put on a mask to cover up greed - God is our witness.
Calvin says
The preachers of the gospel have .. their courtesy and their pleasing manner, but joined with honesty, so that they neither soothe men with vain praises, nor flatter their vices: but impostors allure men by flattery, and spare and indulge their vices, that they may keep them attached to themselves.
