Imagine the vulnerabilities of a watchman who refuses to keep his eyes open to every possible angle from which danger could arise. No doubt the enemy would scout the land observing the bad habits of the watchman. If the watchman fails to examine each point of entry, the enemy will attack from the unprotected angle. In like manner, believers are to walk circumspectly. The word circumspect means to look all around. Believers are to be sober and vigilant knowing that their enemy, the Devil, “walketh about, seeking whom he may devour” (1 Peter 5:8). God’s enemies always search for the weak spot where the hedge has been cut down or ignored. This is why there is no angle in the believer’s life that can be safely ignored.
A tender heart quickly and readily yields when offered correction; however, as a heart becomes hardened, the times of yielding become fewer and farther apart. During the hardening process, the individual finds the true nature of the heart more difficult to grasp. As the heart further hardens, the individual finds himself involved in further defiance. The mischief may start as seemingly insignificant, but a hardening heart will ultimately lead to greater depths of wickedness, some seemingly unimaginable only a short time ago. Some of the worst sins committed in the Bible by God's people were committed by those who shortly before had displayed a tender heart. Yet, they allowed their hearts to be hardened by the deceitfulness of sin.
