(Image: A representation of the “train” or “trolley” scenario. A trolley is shown on a track, and there are two sets of victims. If you don’t pull the lever, 4 people die. If you do pull the lever, the trolley switches to the other tracks, and kills the other person who is tied to the tracks instead.)
In the first Toby Maguire Spider-man movie, there is a scene in which the Green Goblin has train cars suspended from a cable, and sadistically asks Spider-man to make a choice. Will he save his girlfriend, or “suffer the children”. The train scenario is based on the same idea. You are standing next to a lever. One track has four people tied down to it. The other has only one person tied to the tracks. If you don’t pull the lever, 4 people die. But if you do pull the lever, only one person dies. The scenario asks this question: would you pull the lever?
I’ve seen atheists use this scenario as a way of saying “gotcha!” to Christians, to show that they can’t always do the right thing. Using the scenario in this way fails to acknowledge a Christian principle known as the “double-effect” principle. I once heard it said that every good is someone else’s evil. We are only guilty of intended sin. If I don’t pull the lever and save those four people, I am not responsible for killing that one person. That’s because I didn’t intend his or her death.
I understand the purpose of these scenarios. They’re a good way to test one’s sense of ethics. But please, don’t use them as a means to mock Christians. From what I read on Wikipedia’s article, that was not the intended purpose.