To liken something people are familiar with to something new you create understanding. But one danger of analogies is that others might draw the wrong conclusions.
We played a Gospel Analogies game in Seminary on Friday. To show the youth ideas of how analogies work (& also how they can be misconstrued) I read them a scene from the first Shrek movie. Shrek has one thing in mind but Donkey draws all sorts of interesting and irrelevant connections to Shrek's analogy of ogres. It's pretty fun!
Shrek: For your information, there's a lot more to ogres than people think.
Donkey: Example?
Shrek: Example? Okay, um, ogres are like onions.
Donkey: They stink?
Shrek: Yes. No!
Donkey: They make you cry?
Shrek: No!
Donkey: You leave them out in the sun, they get all brown, start sprouting' little white hairs.
Shrek: No! Layers! Onions have layers! Ogres have layers! You get it? We both have layers.
Donkey: Oh, you both have layers. Oh. You know, not everybody likes onions. Cake! Everybody loves cakes! Cakes have layers.
Shrek: I don't care...what everyone likes. Ogres are not like cakes;
Donkey: You know what else everybody likes? Parfaits. Have you ever met a person, you say, "Let's get some parfait," they say, "Hell no, I don't like no parfait?" Parfaits are delicious.
Shrek: No! You dense, irritating, miniature beast of burden! Ogres are like onions! End of story.