This is stolen/paraphrased from Dr. William Lane Craig
For all you atheists who might read this – this is just a though project meant to clear a definition – it is not a trap of any kind. It will help you understand if you actually play along.
Imagine that you are fleeing a lethal storm at the top of a mountain.
As you are careening down the path from the top, you remember that there is a fork in the path coming up soon. You can only recall that one direction will lead you down the mountain (and to safety) and the other path will lead you back around to the top of the mountain (and to certain death)…
But you cannot remember which path is which.
As you come toward the fork, you see one path leading to the right and another to the left. You must get off the mountain. There is no back-tracking. The storm is bearing down on you.
What do you do?
You must take a path; so you take one. You chose left, didn’t you?
You take the left path… too late to go back.
What did you just place in that path? Faith. You are putting faith in it to save you. It either will or it will not, but you placed all of your faith on that path to save you. Faith to take you to the bottom of the mountain… etc.
That is commonly called “blind faith” – you chose left for no reason other than that you just did. Right or wrong.
Now, imagine yourself back in the same situation… but this time, as you careen down the mountain and come to the fork, you notice a sign that you have not seen before.
It has an arrow pointing to the left that says “DOWN” and an arrow pointing right that says “TO THE TOP”…
Now, what do you do?
Well, you choose the left path, of course.
What did you just put in that path? The exact same faith as before – the faith to save you – to take you to safety.
The exact same faith, but now that faith is based in reason, not blind luck… and thus would be called “reasonable faith.”
As you careen down the mountain, you see a man dressed as a forest ranger come down the other path, turn and see you and he yells “Follow me down the mountain!” and heads to the left. Reasonable thing to do? Follow him. Reasonable faith.
You find a map left on the ground by the fork in the path and it clearly indicates that the left path takes you down the mountain. Now when you go left you are being reasonable.
Or any number of other options… with differing levels of confidence, but still reasonable as compared to blind… I am not making any analogies between Christianity, conversion and mountain paths here. I just want people to understand what is meant by the phrase “reasonable faith.”
My faith in Christ is reasonable.
More about Dr. Craig’s ministries at reasonable faith.org