Luke 17:6
And the Lord said, If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it should obey you.
The size of a mustard seed is very tiny and yet it can produce a very big and strong tree. The word of God teaches that all we need is faith the size of a mustard seed.