Proverbs 18
13 To answer before listening - that is folly and shame.
In most preaching situations there is no opportunity to listen to what others have to say first but it is good to do some research beforehand. If I assert that there is a God, how will people react? If I say Jesus can save you, how will they react? Although we will not want to argue over every statement we make, there is merit in taking time to argue the case, at least from time to time.