my cup runneth over

materials required

  • A dark, non-toxic liquid such as black coffeea small cup
  • A pitcher of water
  • A wash basin for catching the water (if the weather is good, you could also perform the experiment outside).


To give children a clear idea of what it means to have a pure, kindly, and radiant heart, perform the following experiment.

First, explain that the cup represents someone’s heart, and depending on what you put in it, that heart will be bright and radiant, or dark and gloomy.

To continue, pour some of the dark liquid into the cup, and place it in the middle of the wash basin. Indicate that the dark liquid represents an unkind act, such as grabbing a toy from a friend, using harsh words with them, and so on.

Next, pour some water into the cup from above. Explain that this water is a kind act, such as apologizing to the friend who was wronged, speaking politely, inviting them to join in a game, sharing cookies with them, and so on.

Continue to pour water into the cup a little at a time, each time noting that this new water represents another kind act. Eventually, as more water is poured into the cup, the liquid inside the cup will become clearer, and it will start to overflow from the cup into the wash basin. Little by little, pour as much water as is needed for the liquid in the cup to be totally clear. Explain that finally, with enough kindness, the heart has been transformed from a dark and gloomy heart back into a bright and radiant one.