The stronger the foundation, the more work which is required to build on that foundation. Sand is a weak foundation, so it is easy to dig a few feet into the sand and bury the anchors for the house. Rock is a strong foundation, so it requires a great deal of work to break through even a few feet.
Jesus contrasts the one who listens to his words and acts to the one who listens to his words and does not act. According to the analogy they have both built a house. Indeed, if we consider the analogy further we can understand that the rock is located under the sand. It is not as if the rock were bare rock. Wherever there is sand, there is bedrock underneath, perhaps 100 feet underneath, but it is there.
So the fool listens to the words of Jesus, nods in agreement, smiles even, then goes home and keeps living. Perhaps, occasionally, he tries to act according to the words that he heard, if it is not too hard. The wise man hears the words of Jesus and begins digging. He digs through 100 feet of sand, hits rock, and begins chipping away at the rock. Only then does he build his life.
It sounds like a lot of work. It is a lot of work. Following Christ requires more than a smile and a nod. It is not easy to build a spiritual life that is anchored in the rock, but it is worth it. As Jesus teaches us, when the winds come and the floods rise, the house built on sand will not stand. We are going to have trouble in this world. We must build our faith to withstand the trouble.
If we listen to the words of Jesus and act on them, a faith will be built in us that cannot be blown over, no matter how strong the winds. If we listen to the words of Jesus and act on them, a hope will be built in us that cannot be drowned, no matter how high the waters reach. Unquestionably, the storms are coming. If we play at being Christian, we are building a play house that cannot stand up to anything. If we take Christianity seriously, more seriously than we have ever taken anything, more seriously than we take money, more seriously than we take sports, more seriously than we take