I get up in the morning, bleary eyed and ready for another day of work. As I stumble into the shower I turn on the water. Suddenly, without any particular reason, I find myself wondering what I would do if one morning the water came out of the tap and, instead of spraying down into the plug, actually floated in mid-air and drifted around the bathroom. Can something so bizarre actually happen? From my own experience of how water acts, and from my knowledge of how gravity works, I conclude that such an occurrence might be possible, but it is highly improbable . . .
After eating breakfast I take the short walk through the morning air and stand at the bus stop. As with many mornings before this one, the sun starts to rise slowly from behind a tall building just east of where I’m standing. I look to the west towards the peaks of a mountain range and wonder: what if one day the sun suddenly rose from the west? Can I say with certainty that it won’t? From what we know about planetary motion, and from the consistency of our historical records, we can say with a high degree of certainty that the sun will rise in the east tomorrow. However, it is possible that there is a law of nature that we are not yet aware of, a law that suddenly changes the direction of earth’s rotation once every 4,5 billion years. So I conclude that the sun rising tomorrow from the west might be possible, but it is highly improbable . . .
I get to work and I’m asked by my boss to fix a computer that is not working. I examine the computer in question and start to hypothesise, in my mind, various possible causes of the problem. I then test each of these possible causes. If the computer isn’t working at all, it might be the power cable that isn’t plugged in. How do I test this? I plug in the cable and switch on the computer. If it still doesn’t work, I theorise that it could be the plug socket that is at fault. How do I test this? I try another plug socket. And so the process of eliminating possible causes of the problem continues, until I find the solution.
This is how I, and any rational human being, solve problems that we encounter every day. This kind of thinking is based on the premise that we live in a universe that is held together by predicable laws, and that effects have natural causes. At no point do I theorise that the computer’s problem is caused by the supernatural, at no point do I hypothesise that small, malicious, invisible bunnies are inside the computer, wreaking havoc with the hardware. It might be possible, but it is highly improbable . . .
At the end of the day I finish work and head out of the office into the street. I’m suddenly confronted by a man carrying a large book and wearing a golden cross around his neck. With kindness in his eyes, and with a soft, caring voice, he tells me an incredible story: a story about how a donkey once spoke; how the sun once stood still; how a woman turned into a pillar of salt; how a man from Galilee was born of a virgin, walked on water, died and rose again; how every human has an undetectable immaterial soul; how unseen creatures, called demons and angels, wage war around us; and how an invisible supernatural being, who created the universe in seven days, sent his only son to die for all of humankind.
Interested, I ask the man a few questions and find out that the only source for most of the story is the book he is holding, translated from manuscripts written thousands of years ago. I find out that the man from Galilee, who is supposed to be alive after two thousand years, can not physically visit us – the only way we can detect his presence is by experiencing him within our hearts.
Disappointed, I walk away, and suddenly realise that the claims of this story are so totally alien to my experience of the world, so totally against the faculty of reason that I use everyday to make decisions and solve problems, and so totally opposed to what we currently know about the universe, that I can only conclude that the story within that book might have possibly happened, but it is highly probable that it didn’t . . .
It is possible that water might float upwards when I jump into the shower next time, but I don’t believe this will happen. It is possible that the sun might rise from the west tomorrow morning when I wait for the bus, but I don’t believe it will. It is possible that invisible bunnies are the cause of computer hardware problems, but I don’t believe they are.
It is possible that Christianity is true, but I don’t believe it is.