Dealing With A Fool

Prov 26:4-5
4 Do not answer a fool according to his folly, lest you also be like him.
5 Answer a fool as his folly {deserves} lest he be wise in his own eyes.
(NAS)

It's interesting that these two verses are found right next to each other. At first glance, they seem to be contradicting each other, but they aren't. There are times when a fool is so unwilling to listen that it is a waste of time to talk to them. There are times when talking to a fool, you can be dragged into being like they are.

Matt 7:6 "Do not give what is holy to dogs, and do not throw your pearls before swine, lest they trample them under their feet, and turn and tear you to pieces.(NAS)

Prov 27:33 A stone is heavy and the sand weighty, but the provocation of a fool is heavier than both of them.(NAS)

There are other times when a fool needs to be exposed, pointed out, or rebuked. Jesus did this many times to the Pharisees and the Sadducees during His ministry. When doing this, careful thought needs to be taken that we are in the right in rebuking others.

The question I have is: "How do I know when to use which verse?" I suppose that as usual, prayer and scripture holds the answer.