Leaving the Old Life Behind

"Beware the leaven of the Pharisees." - Matthew 16:6 Leaven is a small piece of old dough saved from yesterday's batch. It's alive. It's active. And once you press it into fresh dough, it works quietly, slowly, invisibly- until the whole lump becomes like it (Mt. 13:33). Whatever the leaven is, the dough becomes. That's why Scripture uses leaven as a picture of influence. It never stays where you put it. It always takes over. So when God told Israel to remove all leaven (Ex. 12:15), He wasn't just talking about bread. He was calling them to leave Egypt's influence- its worldview, its morality, its shaping power. You don't carry Egypt's leaven into God's freedom. Centuries later Jesus warned, "Beware the leaven of the Pharisees" (Mt. 16:6). Luke tells us: their leaven was hypocrisy (Lk. 12:1)- performing righteousness instead of living it. Matthew adds: it was their teaching (Mt. 16:12)- pressure, appearance, and law added to grace. And even Peter wasn't immune. In Antioch (Gal. 2:11-14), Peter withdrew from Gentile believers when the men from James arrived- Jewish believers from Jerusalem who pressured Gentiles to adopt Jewish customs. Not because he believed their message, but because he feared their disapproval. The old leaven slipped back in- the pressure to perform, the fear of the religious, the instinct to add boundary markers to the finished work of Christ. So Paul confronted him, because "A little leaven leavens the whole lump" (Gal. 5:9). In Romans 6 Paul expands Jesus' teaching: Whatever you present yourself to becomes your master (Rom. 6:16). There are no harmless sins. No pet sins. No private indulgences that stay small. Leaven doesn't stay where you put it. Sin doesn't either. Paul asks, "Shall we continue in sin because we are not under law?" (Rom. 6:15) He's confronting the idea that a believer can keep a little sin on the side- something manageable, something we think we control. But sin is not a pet. It's a power. And if you let it in, it will rise. Before the kingdom's leaven can rise in us, the old leaven must be removed- and kept out.