In his book The Promises of God, William Swan Plumer gives this Biblical counsel and exhortation to the middle-aged:
The middle-aged also have trials peculiar to themselves. The burdens of life come upon them with great weight. As riches increase they are increased also that consume them. They hardly provide for one class of wants before others clamor for their attention.
Their duty is clear: "Cast thy burden upon the Lord, and he shall sustain thee; he shall never suffer the righteous to be moved." Ps. 55:22. What such need is not less toil, or less care, but more resolution and greater confidence in God, who says: "Be of good courage, and he shall strengthen your heart, all ye that hope in the Lord;" "Say to them that are of a fearful heart, Be strong, fear not; behold your God will come with vengeance, even God with a recompense;" "I will strengthen them in the Lord; and they shall walk up and down in his name, saith the Lord." Ps. 21:34; Isa. 35:4; Zech. 10:12.
Strong men ought not to behave like little children, or like the aged and infirm. "Quit you like men, be strong." 1 Cor. 16:13. It is a shame to be chicken-hearted when you ought to be intrepid.
Strong words, but we need to hear them!