We're all building our lives on someone's teaching. Our experiences, hearts, and others teach us one thing and Jesus teaches us another.
Jesus says the wise man will follow His teachings and gain internal stability ("his house will be built on the rock.") The Foolish man, however, will pick someone else's teaching and when the rains come, the floods rise, and the winds blow, his identity and belief system will come crashing down ("his house was built on the sand).
