The word presents truths, the world presents metaphors.
And no one puts new wine into old wineskins. If he does, the wine will burst the skins—and the wine is destroyed, and so are the skins. But new wine is for fresh wineskins.
—Mark 2:22
Metaphors are cultural
If we only use the metaphors used in the scriptures, sometimes we will lose people. This is not because biblical metaphors are ill-conceived, but simply because they reside in a cultural context which is not our own. Many biblical metaphors are based upon an agricultural society and will mean very little to a city church, or deal with practices that are non-existent today as with the quotation above. So besides explaining the biblical illustrations and metaphors, we would do well to also insert parallel metaphors which are more easily understood by our audience.
Of course there is danger in doing so. We must make sure our metaphors are in fact emphasizing the same truth embedded in the biblical illustration. And the only way that will happen is if we ourselves understand the point being made in the original metaphor. Only then can we modernize it.
For example, if I wrongly understood the illustration of the wineskins to be about new things replacing old things, I will supplement it with the wrong illustration. I might say that it is just like getting a new cell phone. You transfer all your stuff over and then stop using the old phone. But this illustration totally misses the point. The point being made in the metaphor is that we ought to live in a way fitting to the current reality. Jesus' disciples were not fasting while he was physically present with them because that would have been totally out of place. It would have been like mourning at a wedding, or patching clothing and preparing wine without using the proper components. Or, if we can supply a modern metaphor that is true to the point, it would be like trying to use a random Android phone cover on my iPhone. The Android phone cover is good, but it will not fit my iPhone. So too we ought to weep when we discover sin in our hearts, rejoice when a friend is born again, fast as we long for Christ's return, and feast with him when that day comes.
Taking our cues from Scripture
As in everything, we would do well to get our wisdom of practice regarding metaphors from the Bible. There, we find a wonderful variety of examples—metaphors which come from daily experiences and from biblical stories, told in full parables and in passing illustrations, piercing to our hearts and at times perplexing our minds.
Naphtali is a doe let loose that bears beautiful fawns.
Genesis 49:21
Circumcise therefore the foreskin of your heart, and be no longer stubborn.
Deuteronomy 10:16
Be not like a horse or a mule, without understanding, which must be curbed with bit and bridle, or it will not stay near you.
Psalms 32:9
First clean the inside of the cup and the plate, that the outside also may be clean.
Matthew 23:26
Woe to you, scribes and Pharisees, hypocrites! For you are like whitewashed tombs, which outwardly appear beautiful, but within are full of dead people’s bones and all uncleanness.
Matthew 23:27
And he told them a parable, saying, 'The land of a rich man produced plentifully...'
Luke 12:16
Destroy this temple, and in three days I will raise it up.
John 2:19
For it is written that Abraham had two sons, one by a slave woman and one by a free woman. But the son of the slave was born according to the flesh, while the son of the free woman was born through promise. Now this may be interpreted allegorically...
Galatians 4:22-24
Refining our illustrations
Let us examine some principles on how to do illustrations well.
1. Know what is primary in the comparison.
Sometimes there are secondary points of comparison to draw out of an illustration or parable. Sometimes there are not. But either way, the primary point of comparison is most important.
For example, in Matthew 23:27 above, Jesus might also be implying that the scribes and Pharisees are unwilling to open up their hearts in the same way that tombs remain closed. Maybe. But this is certainly not the primary point of the metaphor. Thus, I would not want to supplement this metaphor by suggesting that these religious leaders kept their hearts locked up in a safe, impenetrable to Jesus' words of grace. Rather, I might compare them to a sewer.
2. Don't let your illustrations take the spotlight.
We want to use comparisons that will cause our hearts to understand the truth being conveyed; not simply illustrations that entertain us. If people remember your illustration but not the truth behind it (because it is too elaborate, central or disconnected), then it has not served your teaching.
3. Use metaphors when it is helpful.
The fact that you could insert an illustration, does not mean that it is beneficial. Use metaphors where you need them to help people understand or feel the impact of the truths being taught.
4. Keep your metaphors appropriate.
Even if the point of comparison works, metaphors can still be out-of-place if their associations are unfitting to the topic. While wisdom indeed is as sweet as honey to our souls (Proverbs 24:13-14), it is not like a lollipop—because it is not cheap and cavity-causing.
5. Practice how to communicate the illustration, and do not overdo it.
Jokes are destroyed by people who trip over their words when they tell them, or who feel the need to explain the punchline. So too can we ruin our illustrations.
Student examples
Take a listen to the sermonettes below, submitted to this course as assignments. In both instances, the illustrations are very well conceived and delivered. They get our attention and put a sharp point on the truths being conveyed.
The world has first hated Christ by Simon Mawhinney
We've become like the stranger who walks into a private meeting.
People don't like when we leave what they like and claim something better.
Man on Fire by Justin Jeffries
The challenge for us is living in a world that carries buckets full of water intended for one purpose: to quench our fire.
The desert is a hard place to live. There aren't groceries in the desert. There aren't 5 star hotels in the desert.
Have you ever been sitting in a room where there is a fire? Look around at the eyes of the people in the room. You will see many people can't take their eyes off of the flame.