Matthew 17: 20-21 And Jesus said unto them, because of your unbelief: for verily I say unto you, if ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you. Howbeit, this kind goeth not out but by prayer and fasting. ~ Sometimes our problem isn’t a lack of faith but it’s the presence of unbelief in our hearts that prevents our faith from functioning to its fullest. As Jesus points out in this scripture that even the smallest amount of faith is more powerful that any natural substance or thing in this world. But here we see that because of unbelief, their faith couldn’t function to the fullest of its capacity.
According to the timeline of Christ’s life in my Bible, the disciples had been with Jesus for 2 years in his ministry seeing miracles, signs, and wonders. They saw the possessed set free. They believed in the name of Jesus. They ministered and experienced the supernatural in their lives. So it wasn’t that they didn’t have any faith, it was that there was a hindrance that was blocking their faith from working to its fullest. It’s like if you have a container or sink full of water with a stopper in it, the water will not or cannot drain out until you remove the stopper. It’s the same way with faith and unbelief. The container represents the vessel (man), the water represents faith and the stopper represents unbelief. For us to get the water to release, we need to pull the stopper.
Jesus tells his disciples that this kind, this unbelief only goes out by prayer and fasting. Fasting is a spiritual weapon given unto us from the Father to deal with spiritual issues that cannot be dealt with any other way. There are depths of unbelief in our lives that will never be dealt with, dimensions of faith that will never be unlocked unless we are people of prayer and fasting.