There are at least two implications of Jesus’ teaching about kingdom growth in this passage: both kingdom growth within us and among us, though small as a seed at their start, will one day be as large as trees.
First, there will be kingdom growth within us. God’s aim for your life, Christian, is not simply to make you happy. His aim is to make you holy. The good news for us is when God aims for something, He doesn’t miss the mark. If He aims to make you holy, holy you will be. How much different will you be now compared with when Jesus perfects you in heaven? Jesus says you’ll be as different as a tree is from a seed.
Second, there will be kingdom growth among us. Jesus’ kingdom is a spiritual reality now, as He rules and reigns in the hearts and lives of Christians. But it is perpetually moving towards an all encompassing kingdom—spiritual and physical—and will be consummated when Jesus returns. This means the world we all want is coming. It will be ushered in by the one who “offered for all time a single sacrifice for sins.” This is all for God’s glory and the joy of those trust the one who “by a single offering has perfected for all time those who are being sanctified” (Hebrews 10:11-14).