Weak Faith

I heard someone say the other day that "we have weak faith." For some reason that phrase hit me funny and so got me asking the question, is that even possible? Can our faith actually be weak?

Scripture tells us that faith as small as a mustard seed can move a mountain. Here Jesus says it is a matter not not having enough faith.

“You don’t have enough faith,” Jesus told them. 

“I tell you the truth, if you had faith even as small as a mustard seed, you could say to this mountain, ‘Move from here to there,’ and it would move. Nothing would be impossible.” 

Matthew 17:20

There's and entire list of people in Hebrews 11 that made some incredible choices because of their 
faith.  I don't see at any point the scripture claiming that had "strong faith" or "a lot of faith." And it gives the definition of faith with talks about assurance, hope, and confidence.

Faith is the confidence that what we hope for will actually happen; it gives us assurance about things we cannot see. Through their faith, the people in days of old earned a good reputation.

Hebrews 11:1-2

In Jeremiah God called His people Israel faithless.

Therefore, go and give this message to Israel. This is what the Lord says: “O Israel, my faithless people, come home to me again, for I am merciful. I will not be angry with you forever." Jeremiah 3:12

And when Jesus is talking to the people He asks "why do you have little faith" when you see how God takes care of the flowers?

"And if God cares so wonderfully for wildflowers that are here today and thrown into the fire tomorrow, he will certainly care for you. Why do you have so little faith?" 

Matthew 6:30

And faith is a gift of God and nothing that God gives is weak.

For by grace you have been saved through faith;
and that not of yourselves, it is the gift of God;

Romans 5:8

For through the grace given to me I say to everyone among you not to think more 

highly of himself than he ought to think; but to think so as to have sound judgment, 

as God has allotted to each a measure of faith.  

Romans 12:3

And Paul writes of their faith being enlarged.

We ought always to give thanks to God for you, brethren, as is only fitting, because your faith is greatly enlarged, and the love of each one of you toward one another grows ever greater; 

2 Thessalonians 1:3

So I think it is more a matter of the size of your faith or maybe even not having faith at all.  When we appear to have "weak faith" it's a reflection of a belief problem.  We don't believe God and therefore we don't have faith in what He says or who He is.  So let's pray for God to grant us more faith to trust Him!