When a person is sick his strength is less, even though his heart and mind may wish to do as much in God’s service as before. True, all those who will gain everlasting life must ‘exert themselves vigorously,’ but such exertion is not always strictly measured in the amount of work one does. The amount of vigorous activity possible for Epaphroditus in the “Lord’s work” when he was sick would not have compared with what he did when he was well. Yet, as a whole, he was commended by Paul for his exertion.​—Luke 13:24; Philippians 2:25-30.

Changed circumstances, such as illness, may hinder us from fully accomplishing what our heart desires. For instance, the wife of a traveling overseer fell into a major depression. She reported: “All my life I’ve been extremely active and I thoroughly enjoyed my service to God. But then for about nine months, without relief, I had the horrible feeling of being in the ‘pits’ of the earth.” She and her husband had to take a leave from the work of visiting congregations and she was treated by a doctor for her illness. After more than a year she regained her health to the point that they could once again take up this vigorous assignment of service. Presently just as whole-souled as before, she writes: “I’m happy again in my service. But now when I feel overly tired and exhausted, I stay home and rest and try to heed the body’s signals. Now I recognize the symptoms and I’m so thankful to Jehovah that I’m on the road to recovery.”

A person who constantly tries to go beyond his strength could end up with severe depression. The wise man advised: “Do not become righteous overmuch, nor show yourself excessively wise. Why should you cause desolation to yourself? Do not be wicked overmuch, nor become foolish. Why should you die when it is not your time?”​—Ecclesiastes 7:16, 17.

After her recovery she analyzed one of the causes: “Trying not to let anyone down or let any area of my family life or service slacken even a tiny bit, I held to a schedule that left me exhausted. I did this for eight years; and, finally, the doctor said I had ‘burned out.’ Looking back, I feel that even though my reasons for keeping such a schedule were not frivolous, I should have been more reasonable.”