The past several posts (here, here, and here) have discussed Faith and its relation to apologetics. I thought it was fitting at this point to spend a little extra time discussing the question: what is Faith? Certainly there are different definitions of the term, and not everyone agrees on how it ought to be defined in relation to the Bible. It seems fitting, then, to list a few common uses and see what we can say about them.
“Now Faith is the substance of things hoped for, the evidence of things not seen.”Hebrews 11:1
Faith, like many terms in the English language, is used in various ways. Alvin Plantinga, in his book Warranted Christian Belief, mentions three uses. Let’s look at each in turn.
Leap of Faith
The first usage is summarized quite nicely by Mark Twain. He said that faith is “believing what you know ain’t true”. This is where we get the phrase “leap of faith”; it really means something like a leap in the dark. A mother might have faith that her son is still alive even though all of the evidence suggests otherwise. She certainly believes that her son is alive, yet she can’t be said to know he is. The mother lacks evidence and knowledge, nevertheless has faith – or strongly believes – he is still alive. She takes a leap of faith.
Faith as Trust
The second usage is also very common. Here faith would be something like “trust”. One can have faith that the sun will rise tomorrow. That isn’t a leap in the dark, one can have good reason to believe it will rise (given past experience). So faith in this sense is being used as synonymous with trust or confidence. It should be noted here that the first two senses can be had by Christians and non-Christians. An atheist could have faith that science will eventually reveal all there is to know. Now, I don’t believe science could possibly do such a thing , but the point is that anyone can have faith in the first two senses.
The third usage, by contrast, is exclusive to Christianity. One can have faith in this sense if and only if Christianity is true. On this account, faith is knowledge of the Gospel produced in us by the work of the Holy Spirit. Modern thinkers will want to reject the idea that faith is actually knowledge. However, if Christianity is true and the Holy Spirit does instigate belief in the Gospel, then what we would have is knowledge, not merely a confidence or trust. Also notice it wouldn’t be anything like a blind leap of faith. It would be more akin to beliefs produced through memory or sensory organs. These beliefs aren’t blind leaps in the dark. They are produced by some sort of mechanism.
Take memory. After thinking about what you ate for breakfast, you might remember you didn’t eat any. Maybe you woke up late and had to rush out of the door. All you did was think about what you did that morning and found yourself believing you didn’t eat breakfast. Faith would operate like this. Belief in the Gospel would be produced by the Holy Spirit. Maybe you were reading your bible and came to believe what was written is true. The Holy Spirit is the mechanism that makes this happen, sort of like thinking about what you ate for breakfast produces the belief you didn’t eat anything.
The next series of posts will look further into this issue. Can Christians be said to have knowledge of the Gospel if Christianity is true? What are the requirements of knowledge? What are the implications?
 Science literally can’t reveal knowledge about everything. To give just one example, science cannot in principle justify the validity of the scientific method. That would be circular reasoning. Using science to justify science. So if we want to know if science is valid, we’ve got to step outside of the scientific method. Here are just a few other questions that science cannot answer: what is the nature of causation? Are there such things as moral facts? What are the laws of nature? Do abstract objects exist? Do we have free will? What is the nature of time? Does God exist?