Ask the girls if anyone is thirsty. If someone indicates they are thirsty, pull out a pack of Kool-aid (or other unsweetened dry drink mix) and throw it at them saying “Enjoy!” When they look disappointed or irritated, say – “Oh! I guess I forgot something!” and pull out a bag of sugar and give it to them – “Duh – no one would want unsweetened Kool-aid!” And then wait a beat and hit your forehead with the palm of your hand, “Silly me! There are 3 ingredients, and I only gave you two!” Bring out a pitcher of cold water and cups (and a spoon to stir it all together).
Just like all three ingredients are needed to make a tasty drink, they are each unique, but they work together to make a whole, there are three distinct members of the Godhead, each with an important role to play, for one shared purpose.