My flesh and my heart may fail, but God is the strength of my heart and my portion forever. (Psalm 73:26)
You see, there’s a difference between the internal and the external. The external is fading, it’s temporary; but there’s something inside us that’s eternal, that’s from God, that’s linked to God, that doesn’t fade, that doesn’t wither.
Paul says, “Our outward man perishes, but our inward man is renewed day by day.” Whenever I read those words I always think of my first wife, Lydia. Towards the end of her life she suffered from a weak heart and yet she was an amazingly strong and active woman and continued so almost to the last week of her life. And when she felt her heart, her physical heart, failing, that’s what she would say: “My flesh and my heart may fail, but God is the strength of my heart and my portion forever.” She’d learned that lesson that we don’t let the external and the physical dictate to us, that there’s an inner source of life and strength which is not subject to the weakness and fluctuations of our human body.
Eventually God called her home in tremendous victory after almost fifty years of active Christian service and she left behind her a testimony of tremendous victory. But she’d learned that secret: the outward may perish but the inward is eternal. The inward is linked to God, the inward remains a source of strength when there’s little strength left in the outward.