Man is not promised an endless supply of strength for him to store up. Rather, God promises to provide the necessary grace and strength for the present trials.
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).
