Matthew 17:20

And He *said to them, “Because of the littleness of your faith; for truly I say to you, if you have faith the size of a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible to you.

Luke 17:6

And the Lord said, “If you had faith like a mustard seed, you would say to this mulberry tree, ‘Be uprooted and be planted in the sea’; and it would obey you.

Matthew 13:31

He presented another parable to them, saying, The kingdom of heaven is like a mustard seed, which a man took and sowed in his field;

Matthew 21:21

And Jesus answered and said to them, “Truly I say to you, if you have faith and do not doubt, you will not only do what was done to the fig tree, but even if you say to this mountain, ‘Be taken up and cast into the sea,’ it will happen.

Mark 11:23

Truly I say to you, whoever says to this mountain, ‘Be taken up and cast into the sea,’ and does not doubt in his heart, but believes that what he says is going to happen, it will be granted him.

1 Corinthians 13:2

If I have the gift of prophecy, and know all mysteries and all knowledge; and if I have all faith, so as to remove mountains, but do not have love, I am nothing.

Mark 9:23

And Jesus said to him, “‘If You can?’ All things are possible to him who believes.”

Matthew 14:30-31

But seeing the wind, he became frightened, and beginning to sink, he cried out, “Lord, save me!”

Matthew 17:9

As they were coming down from the mountain, Jesus commanded them, saying, Tell the vision to no one until the Son of Man has risen from the dead.”

Matthew 17:17

And Jesus answered and said, “You unbelieving and perverted generation, how long shall I be with you? How long shall I put up with you? Bring him here to Me.”

Mark 4:31

It is like a mustard seed, which, when sown upon the soil, though it is smaller than all the seeds that are upon the soil,

Luke 1:37

For nothing will be impossible with God.”

Luke 18:27

But He said, The things that are impossible with people are possible with God.”

John 11:40

Jesus *said to her, Did I not say to you that if you believe, you will see the glory of God?”

1 Corinthians 12:9

to another faith by the same Spirit, and to another gifts of healing by the one Spirit,

Hebrews 3:19

So we see that they were not able to enter because of unbelief.

Treasury of Scripture Knowledge

Summary

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.

Bible References

Because

Matthew 17:17
And Jesus answered and said, “You unbelieving and perverted generation, how long shall I be with you? How long shall I put up with you? Bring him here to Me.”
Matthew 14:30
But seeing the wind, he became frightened, and beginning to sink, he cried out, “Lord, save me!”
Hebrews 3:19
So we see that they were not able to enter because of unbelief.

A grain

Matthew 13:31
He presented another parable to them, saying, The kingdom of heaven is like a mustard seed, which a man took and sowed in his field;
Mark 4:31
It is like a mustard seed, which, when sown upon the soil, though it is smaller than all the seeds that are upon the soil,

Nothing

Mark 9:23
And Jesus said to him, “‘If You can?’ All things are possible to him who believes.”
Luke 1:37
For nothing will be impossible with God.”
Luke 18:27
But He said, The things that are impossible with people are possible with God.”