Matthew 13:33 / Luke 13:20-21…
Leaven, or yeast, affects the whole batch of dough; it has a penetrating and assimilating nature. Leaven mainly has the idea of something in the past being brought into something in the present. A little of the previous batch had been used as a starter to make the next batch, like when they make sourdough bread. The little piece of leaven turned the new batch into something completely different. Jesus was announcing that the kingdom of God would spread throughout the earth. We should desire that the kingdom of God would spread throughout our life.
The active power in our lives will affect the whole quantity and quality of our life, whether it be the right kind of leaven, the gospel, which is what is being spoken of here, or the wrong kind of leaven, like the corrupting influence of false doctrine and false teachers (Matthew 16:12 / 1 Corinthians 5:6 / Galatians 5:9). Jesus wanted His disciples to be implanted with the leaven of heaven and not with the leaven of legalism. The gospel should inform and inspire all that we do (1 Corinthians 6:18-20, 10:31 / 2 Corinthians 8:7, 9, 9:12-13, 15 / Galatians 2:20 / Ephesians 4:32, 5:25 / Titus 2:11-14).
You are being leavened by the true or the false. It can only be hid for so long before the truth rises up. The inward growth of the active agent will produce the outward manifestation of what is really going on inside you. The bread that is produced proves what ingredients you are using in the bakery of your life. What are you rolling in the dough of your daily living?