Matthew 17:20 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.
A grain of mustard seed is used because of its smallness; being described in Mark 4 as less (in size) than all the seeds commonly sown.
Mark 4:31 It is like a grain of mustard seed, which, when it is sown in the earth, is less than all the seeds that be in the earth:
Jesus had given the twelve power to preach and to heal.
Matthew 10:1 And when he had called unto him his twelve disciples, he gave them power against unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease.
They had been successful until they were presented with the boy who was deaf and dumb, mentally ill and possibly epileptic.
Matthew 17:14 And when they were come to the multitude, there came to him a certain man, kneeling down to him, and saying, 15 Lord, have mercy on my son: for he is lunatick, and sore vexed: for ofttimes he falleth into the fire, and oft into the water. 16 And I brought him to thy disciples, and they could not cure him.
The problem was compounded because the child’s father didn’t believe they could cure him. He wasn’t even sure that Jesus could. Mark gives us additional information.
Mark 9:21 And he asked his father, How long is it ago since this came unto him? And he said, Of a child. 22 And ofttimes it hath cast him into the fire, and into the waters, to destroy him: but if thou canst do any thing, have compassion on us, and help us. 23 Jesus said unto him, If thou canst believe, all things are possible to him that believeth. 24 And straightway the father of the child cried out, and said with tears, Lord, I believe; help thou mine unbelief.
Jesus upbraids them for their lack of belief in the power of God and cures the child.
Matthew 17:17 Then Jesus answered and said, O faithless and perverse generation, how long shall I be with you? how long shall I suffer you? bring him hither to me. 18 And Jesus rebuked the devil; and he departed out of him: and the child was cured from that very hour. 19 Then came the disciples to Jesus apart, and said, Why could not we cast him out? 20 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.
In Mark’s account prayer and fasting are introduced as acts of faith.
Mark 9:29 And he said unto them, This kind can come forth by nothing, but by prayer and fasting.
We might suppose that their lack of faith was because they didn’t view themselves as being part of God’s purpose or having a personal relationship with and access to Him.
Luke 17:5 And the apostles said unto the Lord, Increase our faith. 6 And the Lord said, If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it should obey you.
Jesus is not intending them to believe that they could go about literally removing mountains or sycamine trees, rather that nothing is impossible if it is in accordance with God’s will. He goes on to instruct them that faith is really a matter of understanding that they were working for God and not for their own elevation.
Luke 17:7 But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat? 8 And will not rather say unto him, Make ready wherewith I may sup, and gird thyself, and serve me, till I have eaten and drunken; and afterward thou shalt eat and drink? 9 Doth he thank that servant because he did the things that were commanded him? I trow not. 10 So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.
Jesus’ continual problem with his disciples was their lack of faith (belief).
Mark 4:40 And he said unto them, Why are ye so fearful? how is it that ye have no faith?
Matthew 16:8 Which when Jesus perceived, he said unto them, O ye of little faith, why reason ye among yourselves, because ye have brought no bread?
His teaching was that God’s provision for his creation is self evident.
Matthew 6:30 Wherefore, if God so clothe the grass of the field, which to day is, and to morrow is cast into the oven, shall he not much more clothe you, O ye of little faith?
Without faith it is impossible to please God.
Hebrews 11:6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
We are not in possession of the power of God to do miracles of healing. What God requires of us is to believe the gospel preached by Jesus Christ and obey it.
For this reason the scriptures were recorded.
Romans 10:17 So then faith cometh by hearing, and hearing by the word of God.
John 20:31 But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
2 Timothy 3:15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
John 20:29 Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed are they that have not seen, and yet have believed.
Salvation through faith is conditional upon our response; firstly in baptism for the remission of sins and secondly in a way of life which produces works of faith.
Mark 16:16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned (condemned).
James 2:14 What doth it profit, my brethren, though a man say he hath faith, and have not works? can faith save him? 15 If a brother or sister be naked, and destitute of daily food, 16 And one of you say unto them, Depart in peace, be ye warmed and filled; notwithstanding ye give them not those things which are needful to the body; what doth it profit? 17 Even so faith, if it hath not works, is dead, being alone. 18 Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works.
In this way, faith as a grain of mustard seed will not permit us to perform miracles but it will save us.
I hope you have found this helpful.
God bless you,