Jesus said in Luke 17 that if you had faith the size of a mustard seed that you could tell a mulberry tree to move to the sea and it would obey you. Have you ever tried to move a tree before ? It's not easy. Last year I tried to move a small oleander out of our side yard and I couldn't do it. It took a large truck to move this thing after I had been digging for hours.
It seems like Jesus is saying: do you think this ____________ is impossible ? If you have faith... it can happen. I think I doubt to protect myself. I stay negative and pessimistic so I won't get my hopes up so that when it doesn't happen I can say : "well, I figured that..."
What builds your faith ? ( see Romans 10:17)
Faith comes from hearing...
and hearing by the word of Christ.
Application: how have you found ways to have Christ's word go through you ?