When I was in college, I came to talk to one of the pastors at my church about how we could reach more college students. We talked about moving our only service from 9am to a later time. We talked about including applications and questions relevant to college students, as well as some other possibilities. He listened politely and expressed his concern for the college students I was working with. However, when I finished, he had a fairly brief answer for me. He said something like, “Nic, I know that you want to reach students and give them answers to their questions. But you need to understand that at bottom, their rejection of the gospel isn’t about philosophy, apologetics or better preaching; it’s about unbelief. They don’t want to believe. And when people don’t want to believe there is no reason good enough and no information complete enough. And the university is septic with that kind of unbelief.”

I knew there was something wrong with that answer, but I had a hard time teasing it out. On the one hand, I knew he was partly right. Unbelief is the most recurring sin in the Bible and the most predictable attitude of the human heart. God talks about it constantly, and the narratives of the Bible show us everywhere what it looks like. The prophets explain its fruit and Jesus attacks it regularly. Unbelief is the great sin.

Yet I also knew he was partly wrong. Not every difficulty believing in the Bible is unbelief. Jude says to be “merciful to those who doubt” (Jude 1:22). Even where the word “unbelief” (apistis) is used, there are situations where is it not considered a sin. Like the father that said, “I do believe! Help me overcome my unbelief!” (Mark 9:24).

Yet, even for Christians, unbelief is still the greatest enemy in the mind and heart. It says it this way in Hebrews 3:12-15:

“See to it, brothers, that none of you has a sinful, unbelieving heart that turns away from the living God. But encourage one another daily, as long as it is called Today, so that none of you may be hardened by sin’s deceitfulness. We have come to share in Christ if we hold firmly till the end the confidence we had at first.  As has just been said: “Today, if you hear his voice, do not harden your hearts as you did in the rebellion.”

The author calls the unbelieving heart the “sinful” heart and says that it is the result of our hearts being hardened by “sin’s deceitfulness.” That is, unbelief is a kind of dishonesty and unreality. It is a rebellion against God’s truth: a “turning away from the living God.”

Five biblical categories for difficulty believing in God

1. Ignorance: A lack of education. Not knowing about God’s truth.
2. Doubt: A weakness of heart. When knowledge fails to strengthen the heart with the courage of faith.
3. Non-belief: Having information, we remain unpersuaded. Lack of persuasive reasons to believe.
4. Disbelief: A lack of conceivability. The gospel seems too good to be true, or too bad to be considered.
5. Unbelief: A moral failure to believe what should be believed. A refusal to believe and a subversive attitude. A turning away from God.

Considerations about unbelief

1. Unbelief is the only necessarily damning sin if it persists and ultimately destroys (has “seared” 1 Timothy 4:2) the conscience. Unbelief is the only sin that can inhibit redemption. Faith leads to justification and salvation. Unbelief rejects the only condition of salvation and redemption, and leads to being lost in all its forms: eternity, soul, mental, emotional, identity, and more. Jesus has revealed himself as the redeemer. Unbelief is the only sin that can stop God’s gift of redemption.
2. Unbelief masquerades as all of the other difficulties with belief. Unbelief is united to the flesh that Christians are charged to kill: the mortification of “indwelling sin.” Therefore, if unbelief is seen for what it is, it is seen to be a moral evil. Since we all wish to be good or maintain the feeling that we are good, we cannot suffer a moral evil to present itself to our minds — especially when it is our whole disposition toward God. Therefore, unbelief will mimic all of the other difficulties and is often difficult to tell apart from them. It will claim the need for more information (ignorance), or the feeling that faith is slipping right now (doubt). It may say it needs better reasons for this objection or that (non-belief), or that it is hard to imagine that the truth is real (disbelief). But it will almost never reveal itself as unbelief, unless it possesses a hardened skepticism or belief in another view that makes unbelief seem like a contrary version of non-belief.

How can we know?

How can we know the difference between the first four authentic difficulties and unbelief? On one level, that cannot be simply answered. You have to use the subjective faculty of discernment. It requires honed perception and wisdom. Mentors are helpful. Yet, there is one way I know to use objective criteria to get unbelief to reveal itself: treat each difficulty with its proper treatment and see if it gets better. This works especially with Christians, since they claim to believe the truth, but it can also reveal what is going on with someone who is not yet a believer.

Four treatments

1. For ignorance: Educate them or yourself. Treat the lack of knowledge with knowledge, and see if you or the person having the difficulty eagerly takes hold of the knowledge and applies it vigorously.
2. For doubt: Jude 1:22 says “be merciful to those who doubt.” People who doubt may know much more than you about reasons to believe. Doubt that is not one of the other belief difficulties should first be treated with mercy. If mercy annoys or makes doubt worse, then it is more likely that unbelief is behind that doubt.
3. Non-belief: Provide good reasons to believe. They may have information, but that information needs to be put together in more persuasive groups of reasons. The non-believing person requires faithful persuasion in both word and deed. However, if prolonged persuasion has no positive effect, it is increasingly likely that unbelief lies behind it.
4. Disbelief: Disbelief is cured by aesthetics. After the question of true or false is discussed, there are still more categories that affect how our minds believe in things. Is it beautiful or ugly? Noble or shameful? Wise or foolish? Good or evil? When you’re looking for the block in someone with disbelief or non-belief, there is often some inhibiting idea that is like putting a piece of wood under the wheel of something you are trying to roll. You have to find out what that thing is and remove it. If you can’t find anything, and yet nothing helps the person see the beauty of Christ, it is increasingly likely that unbelief is what lies behind this disbelief.

Vigilance against unbelief

Biblically speaking, everyone lives in the presence of unbelief. Unbelief is connected to the flesh, and we can never fully kill the flesh in this life. Whenever the flesh is creeping back, and whatever sin is holding any ground, unbelief is always growing in that fertile soil. Further, some amount of unbelief is virtually always attending the other difficulties to believe. Last, do not underestimate your own unbelief. Your particular form of unbelief will be more obvious to people who are different than you, especially people who are believers. Unbelief is partly rooted in hypocrisy, and people who are different from us are best at seeing our inconsistencies. That is why whenever we see an idol, sin, bad fruit, or anything in our life indicating that we are out of line with the will of God, we should be on the lookout for unbelief in ourselves. The better you get at finding and dealing with unbelief in the work of the flesh, the more skillful a surgeon you will be in helping others. Not only will you be better at helping them isolate it, but having dealt with that unbelief yourself, you will be much more believable and attractive to those who are seeking any form of real spiritual truth.