What Is the Difference Between Unbelief and Doubt?
The difference becomes clear when we establish a biblical definition of unbelief and a biblical definition of doubt.
Unbelief
It is tempting to just define unbelief as the absence of faith, given that the Greek word used most often (but not always) for unbelief is apistia while the word for faith is pistis. This definition of “unbelief” would be what people have when they just don’t know what the Word says. However, when we survey all the places where unbelief appears in the New Testament, we’ll see that they do not describe conditions where people did not know what God said. Rather, they knew what God said but chose not to act in agreement with what He said, or at least struggled with it. So if we really want to get technical, a better word for not knowing what God says is ignorance. Because some people see the word ignorance as insulting, some people might prefer to use the phrase lack of knowledge. But be careful of confusing people with this verse:
Hosea 4:6:
My people are destroyed for lack of knowledge: because thou hast rejected knowledge, I will also reject thee, that thou shalt be no priest to me: seeing thou hast forgotten the law of thy God, I will also forget thy children.
Preachers like to use this verse to convey the idea that people are dying because they’ve never heard what God says about healing. While that is true, this verse doesn’t prove it. The lack of knowledge in this verse is willful ignorance – the people rejected knowledge. They must have known God’s Law, because God says that they had forgotten it. You can’t forget what you’ve never heard! So this is not a case of “I had no idea that God is the Lord Who Heals Me.” It is case of “I don’t care what God said even though I’ve heard what He said.” (Willful ignorance is also discussed in 2 Peter 3:5-7 where people who had heard of a catastrophic global flood chose to be ignorant of what happened back then.) So Hosea did NOT say that people perish because they’ve never heard about healing!
So let’s go on a tour of all the places in the New Testament where the word unbelief is used. The first two relate to Jesus’ experience at Nazareth:
Matthew 13:58:
And he did not many mighty works there because of their unbelief.
Mark 6:6:
And he marvelled because of their unbelief. And he went round about the villages, teaching.
We cannot say that people at Nazareth had never heard what Jesus could do. That would be wrong because He WAS able to get a few sick people healed there (see Mark 6:1-6 for the whole story). So this unbelief was not from ignorance. After all, He had preached there before! They gave Him an even icier reception the first time – they tried to throw Him off a cliff and kill Him! They couldn’t have been that angry unless they heard His words! And the passage above starts with Jesus teaching in their synagogue some more.
In Matthew 17:14-21, the disciples failed to cast a demon out of a boy because of their unbelief. They certainly knew what Jesus had said – that He had already given them authority over ALL demons (Luke 9:1). In fact, they had already successfully cast out other demons before this incident (Mark 6:12-13), so it wasn’t as if they didn’t know that they had the authority to do it. So ignorance was not the issue. In Mark’s version of this story (Mark 9:17-29), the boy’s father makes an interesting plea – “I believe, help thou mine unbelief.” This shows that interestingly enough, believing and unbelief co-existed to some degree with him. If unbelief were simply the opposite of believing, his statement would make no sense. It would then be the nonsensical statement, “I believe, but help me because I don’t believe.” I think what the man was really saying was, “I know and believe what You say about all thing beings possible to me, but please help me with the fact that this situation looks really awful and my senses are giving me fits because they contradict what You say and I’m being shaken by them.” Whether you agree with that or not, I think you must agree that the man was not in ignorance of what Jesus said – he knew it because he’d just heard it. He was still struggling with unbelief.
In Mark 16:14, Jesus rebuked His disciples for their unbelief regarding His resurrection from the dead. They were not ignorant of what He had said about the matter. He made it very clear that He would be killed and then rise three days later. Their “hardness of heart” hindered them, but they were without excuse in the matter.
Now Paul discusses the Jews’ unbelief:
Romans 3:1-3:
What advantage then hath the Jew? or what profit is there of circumcision?
Much every way: chiefly, because that unto them were committed the oracles of God.
For what if some did not believe? shall their unbelief make the faith of God without effect?
This is not a matter of ignorance either – Paul says explicitly that the oracles of God were committed to them! So they knew that God said. Their response was unbelief – they did not act in agreement with what they knew God had said.
Then Paul discusses Abraham:
Romans 4:20:
He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God;
He knew the promise of God, so it was not a case of ignorance. In Abraham’s case, He believed and acted on what God had said.
The next 4 passages are from Romans 11, where Paul talks about the Gentiles being grafted in:
Romans 11:20:
Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear:
Romans 11:23:
And they also, if they abide not still in unbelief, shall be graffed in: for God is able to graff them in again.
Romans 11:30:
For as ye in times past have not believed God, yet have now obtained mercy through their unbelief:
Romans 11:32:
For God hath concluded them all in unbelief, that he might have mercy upon all.
The Gentiles became the main focus of God’s moving in the earth after the Jews rejected Jesus. Their unbelief led to God having to move through the Gentiles. However, Jesus walked among the Jews and was preached among them. The Jews were not in some distant African tribe that was ignorant of God’s covenant. God’s New Covenant was prophesied throughout the Old Covenant and then came to life before their eyes. So again, we’re looking at a refusal to cooperate with God’s will, not a case of never having heard God’s will.
The next verse is the sole place where ignorance and unbelief come together:
1 Timothy 1:13:
Who was before a blasphemer, and a persecutor, and injurious: but I obtained mercy, because I did it ignorantly in unbelief.
The Greek word for ignorantly does indeed mean without knowledge. Even then, it wasn’t that Paul had no knowledge of Christianity. He HAD to understand what Christians believe because he was throwing Christians in prison! So he had to decide who was a Christian and who wasn’t so that he’d know whom to haul off to jail! However, he had not walked with Jesus in person as the other apostles at the time had done. If those other apostles had turned against Christians, they would not have obtained the same mercy because they could not have pled ignorance the way Paul could.
Also notice that if ignorance and unbelief could be the same thing, it would have been redundant for Paul to use the word ignorantly AND the word unbelief. So I don’t see this verse as a unique verse that proves that ignorance can be unbelief.
The book of Hebrews warns believers not to get an evil heart of unbelief. This was addressed to people who already knew the truth and were already walking in it, not to people who were ignorant of it:
Hebrews 3:12:
Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.
The last 3 places where we see the word unbelief are also in Hebrews. They all refer to the Israelites who did not enter into God’s rest because of unbelief. The Jews knew what God said, but they were dominated more by what they saw than by what God said, so again, this was not ignorance but rather failure to act on what they knew:
Hebrews 3:19:
So we see that they could not enter in because of unbelief.
Hebrews 4:6:
Seeing therefore it remaineth that some must enter therein, and they to whom it was first preached entered not in because of unbelief:
Hebrews 4:11:
Let us labour therefore to enter into that rest, lest any man fall after the same example of unbelief.
So we see that unbelief refers to failure to act on what God says as opposed to not knowing what God says, which would be ignorance. In other words, you don’t even qualify for unbelief until you’ve heard what God says, any more than you can exercise your God-given faith until you’ve heard what God says.
I will note in passing that some of the Hebrews references do use a different Greek word for unbelief from the other passages, but that doesn’t play a crucial role in this discussion.
Now we need to come up with a working definition of unbelief that will fit all the cases above. I think that “not acting in agreement with what you know God said” would cover the bases. Paul wasn’t acting in agreement with what God said (in ignorance, not realizing that God had really said it) before his conversion. In the other cases, people knew full well what God had said, but they didn’t act accordingly. In many of the cases, they allowed sense knowledge to be more important to them than what God said. In others, the issue was that the people hardened their hearts.
Doubt
Now let’s do the same thing with doubt. It is again tempting at first to just say that doubt is the opposite of faith. But the verses below disprove that. Here are all the places in the New Testament where we see the word doubt:
The first is when Peter walked on water, successfully at first. But then he changed his focus from Jesus’ word to the circumstances, and his water walk petered out:
Matthew 14:31:
And immediately Jesus stretched forth his hand, and caught him, and said unto him, O thou of little faith, wherefore didst thou doubt?
The next two citations concern speaking to a mountain and not doubting:
Matthew 21:21:
Jesus answered and said unto them, Verily I say unto you, If ye have faith, and doubt not, ye shall not only do this which is done to the fig tree, but also if ye shall say unto this mountain, Be thou removed, and be thou cast into the sea; it shall be done.
Mark 11:23:
For verily I say unto you, That whosoever shall say unto this mountain, Be thou removed, and be thou cast into the sea; and shall not doubt in his heart, but shall believe that those things which he saith shall come to pass; he shall have whatsoever he saith.
The remaining cases simply refer to being uncertain in mind about something, and they use completely different Greek words that are translated into the English word doubt. This includes phrases like “no doubt.”
The word in Matthew 14:31 is distazo, which appears in only one other place – Matthew 28:17, where Jesus rose from the dead, but some doubted. The Greek word literally means to two-stand. Perhaps a good way to put this would be that they “stood between two opinions.”
The Greek word in the other 2 verses is diakrino. The problem at first is that diakrino is translated all kinds of different ways, including discerning, judge, contending and several other dissimilar-seeming words. It does not seem to lend itself to a tight definition as well as unbelief.
It is also the word for wavering and wavereth in James 1:6, where James warns that you will receive nothing from the Lord if you waver.
It is also the word for “doubting” in “doubting nothing” in Acts 10:20 and “nothing doubting” in Acts 11:12, both of which refer to Peter being commanded to go with the men Cornelius sent.
Doubting, in English usage, involves being unsure or lacking conviction, considering that more than one outcome is possible. This is clearly different from faith, which is being sure of something you can’t see (Hebrews 11:1), in which case only ONE outcome is possible.
Diakrino is another Greek compound word; dia means through and krino means judge. So “through-judge” would be a literal meaning. Do the various translated meanings above have any common thread? It seems that they do. In each case, there is more than one possible conclusion or outcome. Someone is determining or fighting for a specific outcome over another. Someone who is judging may have to decide between two options – “guilty” or “not guilty.” So judging in itself is not a bad thing, and neither is discerning whether one thing is true or another thing is true. Christians are to have their senses exercised to discern good and evil (Hebrews 5:14)!
Thus, someone who doubts is considering more than one conclusion. While that is okay if you’re judging or discerning, it is definitely NOT okay if you are determining what to do in a situation where God has spoken plainly. If God has said something, there should be only one conclusion – God is right and any other conclusion is wrong. So you stick with what God says instead of judging between two opinions – God’s Word and something that contradicts God’s Word!
Interestingly, diakrino is also the word translated staggered where Abraham staggered not at the promise of God through unbelief! So there we see that doubt and unbelief can be at work at the same time.
So What’s the Difference?
It seems that unbelief is knowing what God says but acting the opposite way, while doubt has heard what God says but remains unconvinced – it mentally stands between two opinions.
If you’re unsure of what God says, you’re in doubt, not in unbelief.
Put a little differently, doubt questions God’s Word while unbelief refuses to act on God’s word.
We saw that unbelief can coexist with ignorance (in Paul’s case), but doubt cannot. You cannot doubt that something is true without hearing the statement in question first! Otherwise, there is nothing to question. So you can’t be in doubt if you’re still ignorant.
Certainly, doubt and unbelief can work together. Satan got Adam and Eve to DOUBT that God’s word was true. Only then did they act in UNBELIEF – doing something contrary to what God had commanded.
Here is an example: You are eating in a restaurant and the manager comes in and yells, “Fire! Everybody needs to get out right now!” You could just sit there because you doubt that the person really is the manager, or because you doubt his assertion that there really is a fire. Or you could assume that there is a fire and that the person who said to leave is the manager, but you stay put because you don’t want to abandon your delicious meal and let it get cold on the table. That would be unbelief.
Unbelief Is More Serious Than Doubt
Unbelief is treated as a more serious condition than doubt in Scripture. We saw a reference to an “evil heart of unbelief” but no reference to “an evil heart of doubt.” When Jesus rebuked Peter for doubting, one could see it as a loving rebuke, but when He addressed His disciples about their unbelief in Mark 16:14, he “upbraided” them. Upbraided is translated from the Greek verb oneidizo, which is used elsewhere to denote harsh rebukes. It is the same Greek verb used in Matthew 5:11 when Jesus said “Blessed are ye, when men shall revile you,” in Matthew 11:20 when Jesus upbraided cities, in Matthew 27:44 when the thieves "cast him in his teeth”, in Mark 15:32 when they reviled Him, in Luke 6:22 about being blessed when men reproach you, in Romans 15:3 when men reproached Him, in 1 Thessalonians 4:10 when we suffer reproach, in James 1:5 where God upbraideth not, and 1 Peter 4:14 where you’re told what to do if you’re reproached for the name of Christ. So it is clear that the Lord sees unbelief as more deserving of a stern rebuke than doubt.
When someone doesn’t know much about healing and struggles with it, that’s different from a case where someone has been taught all about divine healing but then won’t cooperate with it because he’s “mad at God” for “allowing” a relative to be chronically ill and/or die.
Can Faith and Doubt Co-Exist?
Yes. Peter was referred to as a person of “little faith” (as opposed to “no faith”) when he doubted. So he was in faith – obviously, he had walked across some water in a storm already. He began to sink when doubt started to get the upper hand, but if he were completely in doubt and not in faith, he would have sunk like a rock immediately before Jesus could grab him.
Jesus spoke of believing and not “doubting in your heart” that something would happen. That’s interesting, because the “heart” is the center of one’s will. Your spirit man can’t be your “heart” because your spirit is already perfect, created in God’s image (Ephesians 4:24) and thus incapable of doubting. Thus, we have to allow for the possibility that you could have thoughts of doubt IN YOUR HEAD and yet still receive what you are believing for as long as that doubt hasn’t gotten into your heart. The presence of a thought of doubt is often just the result of Satan whispering HIS thoughts to you (“It won’t work this time,” “Jesus didn’t really mean what He said,” and so on.) So you could have BOTH faith (in your heart) and DOUBT (in your head) at the same time. But if the doubt is only in your head and you haven’t accepted it, it still won’t stop you from receiving! However, if you accept the thought of doubt in your heart, that is a different story. Now you have two conflicting thoughts in your heart pulling you two different ways, which means that you’re wavering and double-minded. You can tell if a doubt is in your head or in your heart by what you’re saying with your mouth. (See How Can I Tell If Doubt Is in My Heart or Just in My Head?.)
In Matthew 21:21, Jesus made the interesting statement, “If you have faith and do not doubt, you shall…” If doubt were simply the opposite of faith or the absence of faith, that would make no sense. In that case, Jesus’ words would mean, “If you have faith and don’t have the lack of faith…” (which would be redundant) or “If you have a lack of doubt and you don’t doubt…” (which would also be redundant). So doubt must be something that can creep in if you are already BELIEVING, i.e., are in faith.
Interestingly, Doubting Thomas is never called that in Scripture. He didn’t have any nickname that referred to his spiritual condition, but he was really Unbelieving Thomas because Jesus told him not to be faithless (unbelieving) but believing as opposed to not being doubtful but believing:
John 20:27:
Then saith he to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust it into my side: and be not faithless, but believing.
The word faithless here is simply the opposite of the word believing here – the Greek words are apistos and pistos. The leading “a” is a negation, just as an atheist (who doesn’t believe there’s a God) is the opposite of a theist (one who believes there’s a God). Thomas had heard enough of the fact that Jesus would rise from the dead while he walked with Jesus. So he wasn’t in doubt about where Jesus stood on the issue; he was in unbelief.
Can Faith and Unbelief Co-Exist?
Yes. The main in Mark 9:23 said, “I believe, help thou mine unbelief.” So he had both faith (belief) and unbelief at the time. His faith and his unbelief were pulling him in opposite directions and he knew it, which is why he cried for help.
What Do You DO About Doubt and Unbelief?
If you’re doubtful about what God has said, the obvious antidote would be to feed on His Word until you no longer are in doubt about what God says.
If you are in unbelief, it comes down to an act of your will – you must decide to BELIEVE what you know that God has said and act accordingly. Merely stuffing yourself with the Word does not solve the decision issue. You must choose to be a DOER of the Word and not a self-deceived person who only hears the Word but doesn’t do it (James 1:22).
Then adopt Jesus’ solution to fast and pray to keep your flesh under.
See also: