He would water the first plant every afternoon, but the second plant are watered once every two days.
Now, he wanted too see how strong their roots are. So he pull out the plants and the results are clear. He managed to pull out the first plant easily, but the second plant takes longer.
Why would it happen?
Simply because the first plant is spoiled from all the water that it gets daily, and didn't bother to look for other source of waters with its root.
While the second plant didn't get all the waters it needed, therefore it have to search for the water source. The only way is to go deep into the ground with its root. That's why its root are stronger.
How God nurture us is the same as the illustration above. Imagine if God spoiled us by granting all our request and never allowed pains in our lives. Then our root will be weak, and the moment problem comes, we are uprooted.
But God definitely wouldn't do something like that, He loves to train our spiritual root. By allowing pains, problems, pressures of life or every unhappy things that happened. He hoped that we would always search for the true source and grow strong.
When problems come, stand strong!