I did a crazy little object lesson recently. I secretly wrote a mean message on the blackboard about me. Then when students arrived, we discussed that it was likely a disgruntled student that wrote it. I "fessed up" the next day. The point of the lesson was to help us understand the limitations of scientific evidence about origins:

1. Evidence does not speak for itself. It needs to be interpreted. And interpretations can be wrong!
2. Everyone has the same evidence. Creationists and evolutionists, believers in a young earth and believers in an old earth, examine the same fossils, rock layers, etc. Different groups don't have different evidence!
3. Everyone has a bias, including scientists. Their bias may fit or conflict with the Christian worldview.
4. Trustworthy eyewitness accounts trump any interpretation of the evidence. The Bible is God's account of what happened in the beginning--He was there, so He should know what happened!