31 He told them another parable: “The kingdom of heaven is like a mustard seed, which a man took and planted in his field. 32 Though it is the smallest of all seeds, yet when it grows, it is the largest of garden plants and becomes a tree, so that the birds come and perch in its branches.” Matthew 13:31-32
The main interpretation of this parable is the most obvious: the kingdom of God starts small in an area and can burgeon quite quickly. Think of going from one man to twelve disciples to the rest of the world.
One can make a difference in someone’s life.
Of course this is applicable across a variety of settings from friendship to evangelism to visiting the elderly to the business world.
Most of us are not called to conquer the world.
We can have influence over one or two people in a positive way. Soak in that opportunity and make that difference.
You never know what good will come from that influence.