A quick look at what Parables are and how Jesus used them.
What is a parable?
A parable is a story that has a meaning attached to it.
Jesus was not the first person ever to teach in parables but he was a master of this form of teaching.
Jesus had many reasons why he used parables to teach.
By teaching in story form it helps people remember the point that he is trying to get across. We have to remember that during this time information was still generally passed on through speech. That is people didn't write stuff down very much because writing was a skill that many did not posses and writing materials were generally quite expensive. This does not devalue the information that was passed on, because people had become very clever at remembering details that others passed on to them. By teaching in parables it enabled those who heard Jesus to repeat the teaching that much more easily. We also know that Jesus wanted to hide his message from the narrow minded. Only those willing to look for a meaning would find it.
How did Jesus use parables?
However, sometimes we might wonder why Jesus was not more obvious in what he said. By teaching in parables it sometimes made the point available only to those who understood what Jesus was getting at. There are several times in the gospels where the disciples don't get what Jesus has just told them in a parable.
Yet this might be exactly why Jesus uses this form of teaching. A parable requires the listener to work out the point; perhaps also enabling greater change because the meaning belongs to the person who works it out.
It could also be that Jesus needed to avoid upsetting people before he had a chance to complete his ministry. By teaching in parables he was able to not cause offense to those who might stop him preaching. However, there are times in the gospels when Jesus does not hold back from offending people.
I think also, that by relating his teachings to every day events he was able to bridge the gap to other generations. The message of Jesus is still relevant and fresh today because it is discovered and not simply told.