How To Overcome Unbelief

In Matthew 17:20 Jesus said, “if you have faith like a grain of mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move, and nothing will be impossible for you.”
It’s true that some people have more of a measure of faith than others. Some have faith like an apple seed. Some have faith like a peach pip. And some people have the smallest measure of faith – like a mustard seed. Some would conclude that if faith as a grain of mustard seed can move mountains, then they must not have any faith at all, because so far they have been unable to move even a thimble. So then some may ask, “What is the problem? Why haven’t I seen the mountains in my own life moving out of my way?”
The danger of unbelief
Let us consider the context of the verse where Jesus talked about mountain-moving faith. The story is found in Matthew 17:14-21. A certain man with a demon-possessed son had come to Jesus’ disciples for help, but when they could not cast out the evil spirits, they asked Christ why they had been so unsuccessful. He said to them, “Because of your unbelief” (v 20).
This is a very clear and precise explanation that Jesus reiterated by going on to say, “For assuredly, I say to you, if you have faith as a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you”(v 20). So far this seems very straightforward. But the simplicity and clarity of this statement is often overshadowed by confusion over the next words Jesus spoke: “However, this kind does not go out except by prayer and fasting” (v 21).
Casting out doubt
It almost sounds as if Christ contradicted Himself. When asked why the disciples had not been able to exorcise the demon, He said it was because of unbelief. But now He seems to be saying that it is because they had not fasted and prayed enough. Which is it?
The confusion comes when we fail to realise the moral of the story. At first glance it may appear that the demon is the focal point of this account, but a closer look will reveal that the real antagonist in this story is not the demon but the spirit of unbelief. The disciples were concerned about the demon inside the boy, but Jesus was concerned about the unbelief inside His disciples. The disciples’ question was about casting out demons, but Jesus’s answer was about casting out doubt. Christ knew that once unbelief has been cast out, exorcising demons would be a piece of cake.
The key to powerful prayer
Sometimes we have to pray long prayers and fast for many days before we get the victory, but it is not because our appeals coerce God into doing something. And it is not because we have finally earned the answer to our prayers by logging enough credit hours into our spiritual bank account.
Much fasting and prayer may be necessary and useful in helping us gain victory over our own stubborn flesh and cast out the spirit of unbelief that blocks God’s power from flowing through us. It is this kind of unbelief that goes out only “by prayer and fasting.” It is also worth mentioning that some manuscripts do not contain the statement about prayer and fasting at all, which is why many Bible translations have left it out completely. Any way you look at it, faith is the key to powerful prayer. This is the point Christ made in this story.
Remove scornful sceptics
In Matthew 9:25, when Jairus’ daughter died, Jesus had to send everyone out of the room before He could raise her from the dead. Why didn’t He allow all those scornful sceptics to see the miracle with their own eyes? Because He had to cast the unbelief out.
Peter did the same thing in Acts 9:40: “But Peter sent them all out and knelt down and prayed, and turning to the body, he said, ‘Tabitha, arise.’ And she opened her eyes, and when she saw Peter, she sat up.” Jesus taught His disciples a lesson: Cast the spirit of unbelief out, and nothing will be able to stand against you. Demons, death, and even the most formidable mountains will obey your command.
Don’t put all your eggs in one basket
Investors often ‘diversify’ their investments because if one venture doesn’t work out, they want to have something else to fall back on. So a common idiom in the business world is, “Don’t put all your eggs in one basket.” That means, don’t put all your resources into one investment because if one of your ‘baskets’ breaks and all your ‘eggs’ are in it, you will lose everything.
You see, if you are holding back some of your ‘eggs,’ it means you are not 100% confident that a particular basket will hold. You may be 50% confident or even 99% confident, but that small percentage of apprehension is what I am calling ‘unbelief.’ So how do you know when you’ve gotten rid of all the unbelief? When you’ve put all of your eggs into God’s basket.
A sin many ignore
I think many of God’s people don’t realise how sinister and dangerous unbelief is. Many pious and self-righteous Christians look down their religious noses at people committing other, more visible sins. They criticise them sharply without realising that the unbelief they harbour in their hearts, and in some cases enshrine in their doctrines, may be more wicked in God’s sight than the sins they are condemning. Jesus rebuked His disciples for unbelief more than any other thing. The reason unbelief is so dangerous is that not only is it a sin in itself, but it can also be a gateway for other sins as well.
Faith and unbelief do not mix
There have been many wonderful books written and many powerful sermons preached about faith. Indeed, faith is the currency of God’s Kingdom, and without faith it is impossible to please God (Heb 11:6). However, I think many people have a basic misunderstanding about faith. They pray and seek more and more faith. But what if I told you that you already have plenty of faith? The problem is not that you have too little faith; the problem is something else. What if I told you that your faith is already enough to move mountains? Many people will find this hard to accept, but it is very Biblical.
In Mark 9:24 a man said to Jesus, “I do believe; help me overcome my unbelief!” Notice that he didn’t ask Jesus to give him more faith. In fact, he said, “I do believe.” This man recognised that the problem was not too little faith but too much unbelief! Some people think unbelief simply means “no faith.” But it is possible to be an unbelieving believer. In other words, faith and unbelief could be present at the same time. Faith has the potential to move mountains, but unbelief will nullify the power of faith. Let me explain it like this:
Doubt will nullify your faith!  
When my wife was still in Bible college, her father bought her a very special gift: a car! It was a brand-new, silver diesel Volkswagen Jetta. It was a wonderful car that served us well for a long time. One day she lent the car to a friend. On his way to return the car to us, as a courtesy he decided to refill the tank. How he missed the bold red warning on the tank that said to use “diesel only” I will never know! His little mistake was costly for us and devastating for the vehicle. After the petrol was added, the car would no longer run. It’s not that there was too little diesel in the tank. The problem was the injection of a substance that was incompatible with the vehicle’s design. 
This is exactly how unbelief works. The devil wants to inject unbelief into our spirits because he knows it will bring us to a screeching halt. “But let him ask in faith, with no doubting, for the one who doubts is like a wave of the sea that is driven and tossed by the wind” James 1:6. 
Daniel Kolenda is the president of Christ for All Nations Ministries international. For more info: 0861 232 672  or