A person without self-control is like a city with broken-down walls.
In ancient times, cities were often surrounded by walls for their protection. If those walls were breached in any way, the city became vulnerable to attack from a wide variety of enemies. The maintenance of city walls, therefore, was of constant concern.
Proverbs 25:28 likens self-control to a city wall. When we maintain self-control, we keep ourselves safe from forces that would wear us down, attack our weaknesses, and prey on our failures. Scripture warns us that losing our self-control can lead to disastrous results. We may have tendencies to lose our tempers easily, gossip about neighbors or coworkers, or criticize those in authority. We may have an unhealthy desire to own many possessions, an addiction toward food, or an obsession with television. A careless word, a broken promise, or a disrespectful action is an outward sign that our inner wall of self-control has collapsed. Weak self-control makes us vulnerable to living a life of hypocrisy, and then we lose all credibility as a witness to the freedom and joy of the Christian life.
But developing self-control is not just a matter of willing right behavior. We all have experienced the “just do it” break-down. We decide that we will finally regain control of a certain personal weakness only to find a few days later that we have succumbed once again to temptation.
Self-control is not as simple as just “doing it” or “not doing it.” Paul tells us that the Holy Spirit desires to guide our lives. Only he can overcome our sinful cravings and build self-control with staying power. As we turn our moments over to the direction of the Holy Spirit, we will find that we are more often able to resist those things that used to prey on our weaknesses. It is with the power of the Holy Spirit alone that our walls of self-control can be securely maintained.
(From NLT Devotional For Leadership, Dec 16th 2010)