I was doing a word study on the Hebrew and Greek words meaning “to believe”. Here is what I found:
1) The verb “to believe” is closely related to the noun “faith”; basically “to believe”=”to have faith”
2) At the heart of the meaning is the idea of certainty. So, to believe means to be very certain about something. This is in contrast with modern English meaning, which can range from certainty to a guess, as in “I believe there will be good weather tomorrow”.
3) As a logical consequence of 2), having certainty about something often results in action, as you put your trust in it
4) The degree of certainty may vary, e.g. you can have little faith or faith to move mountains.
How do you know you believe in something (in the biblical sense)? I often find people to be poor judges of their faith, tending to overestimate it. The easiest test, quite independent from personal opinion, is to see whether your faith naturally results in a corresponding action. I am intentionally highlighting the word “naturally”, because
1) It is possible that outside circumstances, a punishment or a reward can make you behave in a certain way even though you don’t believe you should. In this case your behavior is not a sign of the faith.
2) You can force yourself to behave in a certain way precisely because you lack faith. This often happens when Christians do not have certainty that God has accepted them as they are, and hence are trying to make up for it with “good behavior”, “acts of righteousness”, as to earn God’s favor. This is the basis for so-called “salvation by works”. Compared to 1), here the action is a sign of having no or little faith.
So, does this mean that if we cannot detect a trace of reward expectation or punishment fear, or lack of faith in our behavior, then it is natural? Well, again, I find people (including myself) to be poor judges of why we do things. Most of us like to think that we do not steal because we are good people, but take away the potential punishment (as often happens in times of war, revolution), and the true character sadly shows up.
I would like to propose the following two tests. They might not work ideally in all circumstances, and may sometimes misclassify some natural behavior as unnatural, but I find them more reliable than others:
1) The natural behavior lasts. This is in contrast with the punishment or reward-based behavior, which only lasts until this punishment or reward is withdrawn. The natural behavior is caused by great inner certainty and hence depends little on outside circumstances.
2) The natural behavior is easy. Here by easy I don’t mean it does not require any effort, but that regardless of how much effort it requires, you can accomplish it with joy. This is in contrast with trying to compensate for the lack of faith, which is emotionally straining, and makes you lose joy as you feel you are never good enough.
While I was trying to be general in my description so far, the Christians, in particular, are called to believe (have absolute certainty) in the gospel. For a Christian, every trace of unnatural behavior should be a sign that he does not believe the gospel nearly as much as he might think. How to change? Admitting this unpleasant truth should be the first step. In the words of boy’s father from Mark 9:24, “I do believe; help me overcome my unbelief!” And He will help.