Perhaps nothing has done as much damage to the Christian religion as when the word “faith” was redefined to mean believing without a reason, or contrary to reason. The idea that faith is belief without a reason has done harm in at least four ways:

1. it has alienated Christians from the God-given ability to reason
2. caused Christians to believe things that they ought not believe
3. caused the church’s ability to defend the faith to atrophy
4. caused some who might have been saved to turn away from the faith, for two reasons:
   1. because Christians too often are fools
   2. because Christians ask them to become fools

What is faith? Put very simply, faith is the confident judgment, based on all available evidence and testimony, that a thing is true. It is to conclude in favor of some statement or proposition. The most powerful kind of faith is faith in God himself. More on that in a minute.

When a person makes a decision about what is true they should consider all the evidence. To refuse to consider evidence is a sort of negligence. It is both unreasonable and also a moral failing. To make an honest mistake in assessing the evidence is, in most cases, only a failure of the mind, but not the heart.

It seems common today to bounce back and forth between two different meanings of the word evidence. We might call them suggestive evidence and absolute evidence. We must distinguish between the two uses or we will get confused.

When we use the word evidence in the suggestive sense, we mean we mean some testimony or a physical fact that points us in a certain direction. In this sense, we may have conflicting evidence. For example, one witness says a man is guilty, the other says he is innocent. Perhaps a man’s car was witnessed at the scene of a crime, but his credit card was used across town at the same time. The evidence points in two different directions.

But another common use of the word evidence is that which inescapably proves something to be true; something for which there is no other explanation. It is rare that any evidence is so strong and so we will rarely have cause to use the word evidence in this way.

Mixing up these two meanings of the word evidence makes conversation almost impossible. One person, using the suggestive sense, says that testimony is evidence pointing in a certain direction. Another person says it isn’t evidence at all because there is another possible explanation, and one which he prefers. The second person is using the word evidence in the absolute sense. He should not do this because it is not an answer to the first man’s point. The danger here is that a person will switch between different meanings of the word in order to ignore evidence that is inconvenient to him. This, as we have said, is unreasonable and immoral.

When we make a decision, we need to come to a reasonable one. This means that the conclusion we reach has to fit with the available evidence, but it means more than that. It also means that the evidence before us must be sufficient to justify our conclusion. That is, being imaginative as we are, we could invent some outlandish explanation that is consistent with the evidence, but which no reasonable person would believe. We would disbelieve the far-fetched explanation not because it gives no explanation for any one piece of evidence, but because the evidence presented is insufficient for such a strange conclusion.

The necessity of sufficient evidence is related to the principle known as Ockham’s razor, which is the preference for simpler explanations. It is a necessary and common sense principle that all of us use in our daily lives. Without it we would have no way to choose between the reasonable and the absurd. There is no limit to the number of outlandish hypotheses we can concoct, but all things being equal, we gravitate to the simpler explanations.

This preference can be trusted in any given situation to guide us away from most false conclusions, but it is not guaranteed to direct us to the truth. Sometimes there is more going on and we simply lack the necessary evidence to reach the true conclusion. We may in some cases postpone judgment in favor of gathering additional evidence.

Postponing judgment brings to mind something else that is sometimes mistaken for faith, we might call it tentative judgment. Tentative judgment is not really faith, because it is not really coming to a conclusion. It is deciding to act in a certain way, despite a lack of confidence. It is the kind of thing where we hedge our bets. Faith is not hedging your bets, but is coming to a definite conclusion and acting according to that conclusion with confidence.

Faith that is based on the statements of God himself is the most certain and powerful kind of faith. Because God is holy, we can trust that he will never lie. Because he has perfect knowledge of everything past, present and future, we can trust that he will never be mistaken. Because he has all power, we can trust that he is able to fulfill every promise he makes. To have God’s word on any subject is sufficient to completely believe it. God’s word trumps all other evidence. His word is absolute evidence and reason would force us to decide in his favor regardless of how much suggestive evidence pointed in another direction. This is not abandoning reason. It is a logically necessary conclusion. God is the expert witness that surpasses all other experts, and what’s more, his character is unimpeachable. If some statement is affirmed by God, we ought to believe it no matter how many others deny it.

Please remember that this is not a suspension of disbelief. That is, God’s statements are true in exactly the same sense as anyone else’s true statement would be. If a historian says that Julius Caesar lived and did such and such a thing, it is either true or false, based on how that statement lines up with what really happened. It is exactly the same with God. If God’s statement lines up with reality, it is true. If it is true, it lines up with reality. The difference is not what kind of truth it is, as if there were different kinds, but merely the reliability of the witness.

Since this is the case, the statements of God are exactly as testable as if they were made by anyone else. If God says that over that hill there is such and such a city, we can go over the hill and see the city. Some of the statements of God in scripture are testable in that way. Other statements are not, but that is because of the kind of statement they are. When God says that he will do a certain thing in the future, we have no way to observe it. But that is the same as when the mayor makes promises. It is just as unobservable.