Teach that we must be very careful the things that we allow in our minds. Put some food coloring in the first glass. Watch how the food coloring changes the color of the water, and eventually colors all the water. Look through the glass and talk about how the food coloring has affected how things look by changing it’s color. Putting things in our minds changes the color in our minds, and it also affects how things look in the world. Put the glob of mud in the second glass. Talk about how the bad stuff (mud) has affected the water. It’s dirty, cloudy, can’t see through it. Let the class try to get the mud out of the water. We should put good things in our water, so that we see things as they are. You could get the dirt out by lots of hard work, straining it, distilling it, etc. Remind the class that through the Atonement, our water can be cleaned, but it’s a lot easier to make good choices so we don’t have to clean out our minds. Other uses: This object lesson was told to me at a presentation by Joann Hamilton (http://www.StrengthenTheFamily.net/) as a lesson for teaching children the importance of avoiding pornography specifically, though it has application for the Word of Wisdom and Chastity.