We were looking at the story of David and thinking about who our real friends were- who could we trust?
I poured some hot milk out of a thermos into a clear glass bowl. The milk shows us what our friends appear to be, warm and comforting. However, I then added some vinegar to the milk and it started to separate into curds and whey. The vinegar represents difficult things that happen in life. The friends may start to separate, as the milk does, into those who are solid and dependable and those who are watery and insubstantial. We drained the whey away so that only the curds were left. God is solid like these curds. He is a friend who will never drain away when things get difficult. When everyone else has drained away, he will always be close ro us. We then introduced the verse below as something to remember.
A man of many companions may come to ruin, but there is a friend who sticks closer than a brother. Proverbs 18:24
This is a brilliant book, containing lots of object lessons like this one. I've never actually used an experiment from the book for the purpose it was originally designed, but I've used lots of them to illustrate other points!