Diligence is the constant application of energy to complete a task or given responsibility.  Further, it is exerting ourselves with constant focus and energy to accomplish a given task without any unnecessary delay.  

The word diligence comes from the Latin word diligo, meaning to love in earnest.  The definition of diligence also the responsibility to chose.  The Latin word  dis and lego mean to chose the very best, while completely ignoring the unimportant.  

The concept is further seen in the Hebrew word, kharoots, meaning to stir oneself into action or move.  The Greek word, spooday (spoudh) emphasizes speed, hast, and to urge someone on. 

The full meaning of diligence may be seen as, demonstrating a willing urgency and thoroughness to complete a given task, due to its importance. 

Be diligent.  Work on each task with urgency until it is completed.  There is great satisfaction when any task is completed properly:  praise from the one who assigned the task, a sense of well-being for a job well done, an upgrade in responsibilities by those in authority over us, and not wasting our time on trivial pursuits which do not produce character in our lives, or in the lives of others.