This is a great activity for young students to do to illustrate the Parable of the foolish man building his house on the sand. Matthew 7:24-27 The Message.
Start with a tray of play sand. Have the students build up the sand as firm as possible. Then used blocks or Lincoln logs to construct a house. 
Punch 2-3 holes in the bottom of a plastic cup. Fill the cup with water. Hold the cup above the house built on the sand. The water will drip out of the holes in the bottom of the cup to represent rain.
The students will observe the sand getting wet and collapsing, causing the house to collapse and lean. This activity proves that we must build on a solid foundation to withstand rain and storms. 
Jesus is the solid rock foundation upon which to build our lives.











