Why did Jesus speak in parables?

Jonathan Edwards notes five reasons:

1.) It was an engaging way of instruction.

He is condescending to our weakness and using easy and familiar ways of speaking to teach us.

2.) It was a very instructive way of teaching.

The reason of something is often seen through comparisons that otherwise would be very difficult to explain.

3.) So that we might have some exercise for our understandings to find out the truth contained in them.

God gives us the gold, but he gives it to us in a mine that we might dig for it and get in a way of our own industry. This makes the discovery of truth even more pleasing. If gold were thrown plentifully before every man’s face, and everyone could have it without any labor or industry, it would not be prized as it now is.

4.) Because many people were not capable of receiving gospel truths plainly declared.

5.) It was that those that had honest hearts and pleasure in the truth and sought it out might understand it, but that others might not understand it.