Once you mix leaven into your dough, there’s no way to avoid it spreading through the whole lump. In the same way, the kingdom of God is unstoppable. No one can keep it from penetrating society. The amazing thing is, it spreads and increases through simple, individual people like you and me.
How does this happen? Your life is connected to a bunch of other people’s lives: your close friends and family, your work relationships, your acquaintances… even the barista at your favorite coffee shop. In turn, each and every one of those people is connected to a whole slew of others. Right now, all the humans alive on the planet are connected to each other through this massive network of interpersonal connections.