The human heart is like receptive soil to the seed of the Word of God. Jesus used this analogy in the parable of the sower (see Mark 4:3–20). The soil that the seed fell on represents four categories of hearers' hearts, four different reactions to the Word of God: the hard heart, the shallow heart, the crowded heart, and the fruitful heart.
First, there is the hard heart, the seed that falls along the roadside. This represents people who hear the Word of God, but never really believe.
Then there is the shallow heart. That is the seed that falls on stony ground. This signifies the people who hear the Word of God and receive it with joy, but because there is no root to sustain them, they wither.
Next, there is the crowded heart. That is the seed that falls on ground where weeds choke out its growth. Slowly and surely, these people, busy with the cares and riches of the world, just lose interest in the things of God.
Finally, there is the fruitful heart that receives the Word. The seed falls on good ground and the plants produce a rich harvest.
We are the ones who determine what kind of soil our hearts will be. We decide whether we will have a hard heart, a shallow heart, a crowded heart, or a receptive heart. This is exactly what James meant when he said, "Therefore lay aside all filthiness and overflow of wickedness, and receive with meekness the implanted word, which is able to save your souls" (James 1:21).
The Word of God cannot work in our lives unless we have receptive hearts.