Unfortunately, some Christians have become convinced that old age serves as a sufficient excuse for a lack of service to the Lord’s work. Granted, the field of one’s service may change, but there should always remain a willingness to serve. For instance, Moses received his initial call to deliver Israel at forty years old (Acts 7:23) but did not lead God’s people out of Egypt until he was eighty (Exodus 7:7). When he died at 120 years of age, he remarked that “his eye was not dim, nor his natural force abated” (Deuteronomy 34:7). At forty years of age, Caleb received a promise from Moses concerning the possession of land in Canaan (Joshua 14:7-9). Forty-five years later, Caleb took possession by driving out the mighty Anakims (Joshua 14:10-12). Caleb did something in his old age that many of the young men could not or would not attempt (Joshua 17:13).
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.
