That same day Jesus went out of the house and sat by the lake. … Then he told them many things in parables, saying: ‘A farmer went out to sow his seed…’ (Mt 13:1, 3, NIV, emphasis added).

Interesting… is Jesus, perhaps, acting out the parable as he tells it?

I think he might be.

The parable of the sower is about some people who hear but don’t understand (like the seed that falls on the path), and other people who hear and do understand (like the seed that falls on the good soil).

Jesus tells the parable twice: first to a crowd of people who won’t understand it (because he doesn’t tell them what it means), and then he re-tells it to his disciples, in such a way that they would understand it (because he tells them what it means). Between these two tellings of the parable, Jesus explains what he is doing:

The disciples came to him and asked, ‘Why do you speak to the people in parables?’ (v.10)

In other words, why do you speak to them using an obscure story without explaining what it means?

He replied, ‘Because the knowledge of the secrets of the kingdom of heaven has been given to you, but not to them. Whoever has will be given more, and they will have an abundance. Whoever does not have, even what they have will be taken from them’ (v.11-12).

By telling the parable twice, first to the crowd without explaining what it means, and then subsequently explaining it to his disciples, Jesus provides a clear demonstration of the truth the parable itself is intended to convey: that some people are given insight so that they understand the message about the kingdom, but other people are not; some people ‘have’, but other people ‘do not have’.

But why do Jesus’ disciples understand the parable, while the crowds do not?

Because the knowledge of the secrets of the kingdom of heaven has been given to you…

Understanding is a gift. Without that gift being given to us, we would not understand the message of the kingdom. Without God revealing the truth to us, we wouldn’t understand it (see Mt 11:25-27).

But why do we need to be given this understanding? Why don’t we understand it without needing it to be revealed to us? Jesus gives the answer, from Isaiah 6:

For this people’s heart has become calloused;
  they hardly hear with their ears,
  and they have closed their eyes (v.15).

It’s not that we don’t have enough evidence, but (whether consciously or unconsciously) we close our eyes to the evidence before us. The Pharisees in the previous chapter are an excellent example of that:

Then [Jesus] said to the man, ‘Stretch out your hand.’ So he stretched it out and it was completely restored, just as sound as the other. But the Pharisees went out and plotted how they might kill Jesus (Mt 12:13-14).

Like many Christians, I can remember when I first understood the message of the kingdom. I had heard it week by week through my childhood, but I don’t think I had the faintest idea what it was all about. My eyes were closed, and my heart was hardened. But then, when I was fifteen, the Lord suddenly opened my heart to respond to the message of the kingdom (see Acts 16:14). Suddenly it was clear: Jesus had died for me, God loved me, and wanted me to follow him! How had I not realised it before?!

The parable is a reminder that the kingdom is growing according to God’s plan. He fills us with his Spirit and sends us out with the good news of the kingdom. Some people don’t understand it at all (the path), some people receive it at first but quickly fall away (the rocky ground), and some people’s faith is choked by the cares of this life (the thorns). But, by God’s sovereign grace, some people genuinely understand the good news (the seed sown on good soil) and then go on to bear much fruit. And that’s how the kingdom grows.