You have read the parable of the sower and the seed (Luke 8:4-8).
Notice that Jesus did not begin it by saying, “The Kingdom of Heaven is like…” He just started telling the story. When His disciples asked for an explanation, He described people failing to become believers, people becoming believers but not having the strength to bear tests, or the focus to bear fruit, and finally, successful believers. These listen to what God has spoken to them, hold on to it, endure the tests that come with it, and as a result of this type of life, bear fruit. It is a description of living in the Kingdom as believers. The Church at work in the Kingdom.
“This is the meaning of the parable:The seed is the word of God. The seeds along the path are those who have heard. Then the Devil comes and takes away the word from their hearts, so that they may not believe and be saved. And the seeds on the rock are those who, when they hear, welcome the word with joy. Having no root, these believe for a while and depart in a time of testing. As for the seed that fell among thorns, these are the ones who, when they have heard, go on their way and are choked with worries, riches, and pleasures of life, and produce no mature fruit. But the seed in the good ground—these are the ones who,having heard the word with an honest and good heart, hold on to it and by enduring, bear fruit.”