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.” (Matthew 17:20, ESV)
I was actually planning for a session that would teach about this from the gospel of Mark instead! If you pray and ask for something, what is it actually that you’re doing? Is it a request to God for something? Or that you’re giving up on your own efforts and begging God to help you? That placement of God above you, that’s depending on God only and that’s faith. That moves mountains.