When we speak about knowing things as Christians, one thing to remember is that the way we use the word faith is very different than the way our culture typically uses the word. Most people use the word to describe something other than knowledge. If you have faith, it is because you believe something, but that doesn’t actually indicate whether that thing is true or not. People say “faith” and “belief” especially about things they don’t think can be proven, tested, or known to be actually true. Hence, you’ll often hear sentences like, “Well, you can believe that, but you can’t know.” It is a discussion worth having, but we need to remember that in the bible “faith” does not mean, “something you think when you can’t know.” Rather, it means something more like, “trusting someone or something to be faithful to do what He or it is supposed to do.” Really, “trust” is a better word here. Hence, faith may look like our trust in the words God has spoken about Jesus being raised from the dead, even if we have not physically seen Christ in His resurrected body. That’s one way to understand what Jesus said to Thomas in John 20:29.
Francis Schaeffer has a great parable about this, relating it to climbing a mountain and getting lost in a fog…
“Faith” Versus Faith.
One must analyze the word faith and see that it can mean two completely opposite things.
Suppose we are climbing in the Alps and are very high on the bare rock, and suddenly the fog shuts down. The guide turns to us and says that the ice is forming and that there is no hope; before morning we will all freeze to death here on the shoulder of the mountain. Simply to keep warm the guide keeps us moving in the dense fog further out on the shoulder until none of us have any idea where we are. After an hour or so, someone says to the guide, “Suppose I dropped and hit a ledge ten feet down in the fog. What would happen then?” The guide would say that you might make it until the morning and thus live. So, with absolutely no knowledge or any reason to support his action, one of the group hangs and drops into the fog. This would be one kind of faith, a leap of faith.
Suppose, however, after we have worked out on the shoulder in the midst of the fog and the growing ice on the rock, we had stopped and we heard a voice which said, “You cannot see me, but I know exactly where you are from your voices. I am on another ridge. I have lived in these mountains, man and boy, for over sixty years and I know every foot of them. I assure you that ten feet below you there is a ledge. If you hang and drop, you can make it through the night and I will get you in the morning.”
I would not hang and drop at once, but would ask questions to try to ascertain if the man knew what he was talking about and if he was not my enemy. In the Alps, for example, I would ask him his name. If the name he gave me was the name of a family from that part of the mountains, it would count a great deal to me. In the Swiss Alps there are certain family names that indicate mountain families of that area. In my desperate situation, even though time would be running out, I would ask him what to me would be the adequate and sufficient questions, and when I became convinced by his answers, then I would hang and drop.
This is faith, but obviously it has no relationship to the other use of the word. As a matter of fact, if one of these is called faith, the other should not be designated by the same word. The historic Christian faith is not a leap of faith in the post-Kierkegaardian sense because He is not silent, and I am invited to ask the adequate and sufficient questions, not only in regard to details, but also in regard to the existence of the universe and its complexity and in regard to the existence of man. I am invited to ask adequate and sufficient questions and then believe Him and bow before Him metaphysically in knowing that I exist because He made man, and bow before Him morally as needing His provision for me in the substitutionary, propitiatory death of Christ.
[This is Appendix B in He is There and He is Not Silent]