It has been a very cold winter, and a few days ago the church snow blower decided it had had enough. Every time Bro. Mahar turned off the choke, the engine would sputter and die. After a bit of trial and error, we loaded it onto the back of my truck and brought it over to Kevin to take a look. Interestingly enough, he started it right up, and the problem disappeared. His best diagnosis was simple: water in the gas line. Just a little moisture had been enough to disrupt the entire system, but once it worked its way through, the engine ran as it should.

As I drove back to the office, that small mechanical issue stayed with me. Something so minor had caused so much trouble. The Apostle Paul used a similar picture when he warned the church at Corinth that “a little leaven” affects the whole lump. In Scripture, leaven often pictures sin—not because it is always loud or obvious, but because it quietly spreads. A small allowance, a tolerated attitude, or an unchecked habit can slowly influence far more of our lives than we ever intended.

We could spend hours talking about sowing and reaping, but the more sobering truth is that sin often affects us in ways we don’t immediately see. The book of Hebrews warns us about bitterness—something that can take root quietly and then grow until it troubles many. What begins unseen in the heart eventually works its way into our words, our relationships, and our testimony. Like water in a fuel line, it interrupts spiritual power and forward motion.

Kevin’s advice for the snow blower was simple: keep snow from getting into the gas tank. It made perfect sense. That water would sit there unnoticed until it was drawn into the engine and caused everything to stall. Scripture gives us similar counsel for the Christian life. Hebrews exhorts us to lay aside every weight and the sin which doth so easily beset us, so that we may run our race with patience. A clean heart keeps the spiritual lines clear, allowing us to move forward freely and faithfully for the cause of Christ.