And these are they likewise which are sown on stony ground; who, when they have heard the word, immediately receive it with gladness;
Note 5 at Mr 4:16: The second type of person that Jesus described is one who does receive the Word, even with great joy, but whose commitment to the Word is shallow. Just as a plant must establish a strong root system to sustain its growth, so we must become rooted and grounded in God's Word (Eph 3:17; Col 1:23, and 2:7). Too much attention on visible growth will cause us to become impatient and not take the time to become firmly established in the truths of God's Word. This will always result in fruitlessness.
A seed planted in shallow soil will germinate and grow faster than a seed planted in deep soil. The seed in deep soil will put all of its energy toward the roots first, while the seed in shallow soil has no choice but to put its effort into the growth of the plant above the ground. The plant in shallow soil will look like it is far ahead of the other seed for a while, but that will not last. It soon withers and dies, while the seed with roots grows and brings forth fruit.
Likewise, some Christians get very excited over the promises of God's Word but make the mistake of not getting firmly established in those truths before they "jump out on a limb" with them. This kind of people withers away when the heat is on. We can't live off of someone else's commitment to the Word; we must have root in ourselves (Mr 4:17).
Notice that afflictions, persecutions, and tribulations are instruments of the devil and are used to stop God's Word from bearing fruit in our lives. They are not good things that God brings our way to improve us. They are instruments of Satan. These things are designed to take our attention off of God's Word, thereby stopping the Word from taking root in us. It's like the runners who spend all of their time in the grandstands arguing with the hecklers over the way they're running the race. They may win an argument, but they will lose the race. We must not let anything distract us from meditating on God's Word day and night, for then we will make our way prosperous and then we will have good success (Jos 1:8). By consistently putting God's Word in first place in every area of our lives, we will let that Word become so rooted in us that nothing can get it out.