Puzzling Passage: Matthew 17:20
Jesus speaking to His disciples:
20 He said to them, “Because of your little faith. For truly, I say to you, 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.”

Why it is Puzzling:
The passage seems to suggest that as long as we have faith, we can command the impossible to happen. Yet personal experience, or even Bible experience shows that our prayers don’t always work. This verse makes us, disciples of Jesus feel so powerful, that we can do the impossible! But in reality, when we pray; when we command things to happen, our confidence level doesn’t really line up with this verse.

Alternative interpretation #1
This passage is really just saying that as long as our prayers are in line with God’s will, it will work – God is sovereign.

>> This is a convenient explanation. “God is Sovereign” – who dares argue with that? So whenever prayer doesn’t work, just blame it on God’s sovereignty. One simply can’t go wrong with that. However, Jesus didn’t qualify His statement. Jesus did not say that we can move mountains provided the mountain movement is in accordance with God’s will.

Alternative interpretation #2: 
This passage is specifically spoken in the context of casting out demons, or healing caused by spiritual warfare/ demonic powers. So the mountain is a picture of demonic powers.

Verse 14-20 offers the context:
Jesus Heals a Boy with a Demon
14 And when they came to the crowd, a man came up to him and, kneeling before him, 15 said, “Lord, have mercy on my son, for he has seizures and he suffers terribly. For often he falls into the fire, and often into the water. 16 And I brought him to your disciples, and they could not heal him.” 17 And Jesus answered, “O faithless and twisted generation, how long am I to be with you? How long am I to bear with you? Bring him here to me.” 18 And Jesus rebuked the demon, and it came out of him, and the boy was healed instantly. 19 Then the disciples came to Jesus privately and said, “Why could we not cast it out?” 20 He said to them, “Because of your little faith. For truly, I say to you, 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.”

>> This interpretation flows well from the section before (v14-19). Note that Jesus is merely using an illustration. Nowhere in the Bible does it show a person praying for a mountain to be moved. So the mountain being a picture of demonic powers is very plausible. When you cast out demons, the demons change location, they are not destroyed, so it fits the picture of moving mountains. Mountains are also hard to move. Demons are also hard to get rid of. In fact, it is impossible for men but possible only for God. So just a small mustard seed faith in God will do in getting rid of demons.

>> Some may argue that such an application is too narrow. Is it possible to have a wider application? Can it be applied to commanding the weather; commanding sicknesses caused by natural causes; commanding exam results or perhaps commanding a presidential election? Jesus did say “NOTHING will be impossible” – so the question is what does “nothing” encompass? Shouldn’t we consider the “nothing” in its context also? For example, if somebody accuses you of leaking information. Thus you defend yourself and say, “It is not me! I know nothing!” Actually, you don’t mean you have zero knowledge of anything, but that you know nothing pertaining to the leaked information. So the use of “nothing” in the passage is likely pertaining only to the spiritual warfare context.

Conclusion: 
This verse is not a blank cheque to get whatever we want to happen. It gives us confidence when it comes to spiritual warfare. It is not the quantity of faith that matters but the object of our faith that matters – as long as we cast out demons in Jesus’ name; as long as we depend on His power and authority, we are guaranteed to succeed. Demons must flee.