Kathryn
It was on fire when I laid down on it.
I've heard a few variants of that snake and mouse story too. I've never liked the story's suggestion that people can't change. One of Jesus' teachings I've always liked is that we should be willing to forgive since people can change. Just because a person made bad choices in the past it doesn't mean that they have to keep making them in the future.
That's all well and good, but as a Christian, I apply Jesus' teachings to MYSELF and don't expect others to necessarily follow them.
The way this plays out is that I am responsible for my own actions and I allow other people the freedom to be whoever they want to be. Sometimes this means that I have to accept that they are not going to change - at least not on my terms and timing.
That's why we have credit scores, background checks, and risk management departments. The best indicator of future performance is usually past performance.