Luke 17:6

So the Lord said, “If you have faith as a mustard seed, you can say to this mulberry tree, ‘Be pulled up by the roots and planted in the sea,’ and it would obey you.”

The Lord said if we have faith with all the potential of a mustard seed. The scripture isn’t referring to the size of the mustard seed, but the potential of seed faith. This isn’t head faith, but revelation faith from meditating on the word of God. It comes down to what we believe and how much we want to promises of God in our lives.