Life gives us many real-time experiences, that teach spiritual principles. Whether in parable form or symbolic form, we have to look at life in order to understand the things that are beyond this life.
When the spiritual life fails there is a sensation of panic or anxiety, of lost strength, and the failure to see things in their true reality.
The heart throbbing, is taken from the activities of a hustling traveler merchant who goes from place to place rapidly, seeking buyers for his wares. And this is an expression of the pain and distress as indicated by the rapidly beating heart, due to the uncertainty of the merchants future.
Failing strength, describes the weakness of physical strength as well as mental strength.
The light of the eyes, describes the failing ability to see and understand, and the confusion as to why things are the way they are.
And so the continued failure of the individuals life, due to the lack of spiritual resources, is being described.
Just as the physical body fails because of a poor diet, because of injury, because of sickness and disease, so too, the soul fails because of the lack of proper nourishment that is provided by a daily Bible study, and because of a lack of proper exercise that is provided by the application to ones life, of the Bible doctrine that is learned.
Most people pay attention to their physical life to some extent.
However, most people do not pay attention to the spiritual life.
And while physical and mental ailments are more than obvious in this life, likewise on the spiritual side of life, those ailments are not so obvious, but they are just as real, and even more so.
To ignore your spiritual life, to ignore your daily Bible study, to ignore your daily activity in the application of Bible doctrine to your life, will result in a failed life.