In defining the Kingdom of God, Jesus uses imagery (pictures) that common folks, who made up most of His audience, would understand. He made reference to the mustard seed (Mark 4:30; Matt. 13:31; Lk 13:18) which is the tiniest seed in existence, which when fully grown becomes an oak tree - a huge tree on which birds perch.
Which farmer would not have understood the lesson Jesus was teaching? It is a daily reality for them. They saw this around everywhere.
Jesus was teaching His audience that His kingdom, little as it was then, has great potentials in the future.
Today, the Kingdom of God has spread all over the world and is continuing its expansion.
He also compares His Kingdom to 'yeast in dough'. How a pinch of yeast can make dough much bigger to become bread.
Jesus was not only telling His audience a story. Today this has become a reality under our very eyes. In fact Jesus' words then still ring in our ears today. He is extending a hand of welcome to all and sundry - irrespective of colour, race or creed to become kingdom subjects because this kingdom's growth and size no power on earth can contain or resist. The benefits are humongous (extremely large and impressive).
Today, if you should hear His voice harden not your hearts.(Ps 95:7)
Jesus is Lord!