This life offers only a window of time and opportunity to work for the Lord. Youthfulness and old age both offer their own hindrances to service. In many ways, though not entirely, youth should be spent in learning, middle age in doing, and old age in teaching those who are learning and doing. Many of the greatest servants of the Lord found in scripture began their journey in youth by learning of the Lord and His ways (1 Kings 18:12; Psalm 71:5; 2 Chronicles 34:3; Job 29:4; Ecclesiastes 12:1). As they approached the prime of life, they invested their learning by serving the Lord (Numbers 8:24-25). As they passed their prime, they would pass their knowledge on to the next generation in hopes of the Lord’s work continuing and flourishing (2 Timothy 4:1-8)..
From youth, man is gripped by sin’s attraction. As he ages, the source of temptation may vary, but the fact that he is tempted remains constant. Paul instructed young Timothy to “flee . . . youthful lusts” (2 Timothy 2:22), yet Solomon’s heart was turned after other gods when he “was old” (1 Kings 11:4). Many believers have wasted the precious years of youth by succumbing to the youthful lusts of which Paul warned Timothy. Others have fought the good fight in their youth, only to regretfully compromise in their waning years. There is no time or age for the believer to be at ease concerning sin. Sin can be pleasurable but is always deceptive with uncertain outcomes for those who indulge.
Believers should be zealous of good works, but their zeal must not spring from a position of ignorance. The Bible points to the Jews as a zealous people, but their zeal was not according to knowledge. Nobody worked harder trying to reach a righteous state than did the Jews. However, they failed to realize that true righteousness comes as an unmerited gift from God. Yet, the Jews were “ignorant of God's righteousness,” and went “about to establish their own righteousness” (Romans 10:3). Paul repeatedly testified concerning the futility of trying to earn God's favour through one’s own efforts (Acts 22:3; Philippians 3:6). Before Paul came to know Christ, he thought he should fight against Christ’s followers and zealously persecute the church of God. He even placed many of the new believers into prison and caused their deaths. Yet, he declared that all this was done in ignorance (1 Timothy 1:13). He, like the Jews, had a tremendous zeal, but that zeal was not according to knowledge.