When I was a young girl, I had a glass necklace with a tiny mustard seed in the center. Despite its size, that seed could grow into a great tree.

[For example], Jesus tells a parable about somebody who takes a mustard seed, plants it in the ground, and it grows up to be a great tree, or a bush at least, a weed, though, in plain language.

The importance of the parables can hardly be overestimated. They comprise a substantial part of the recorded preaching of Jesus ... (Lk 15:8-10); this is how seed always grows to full harvest ...