Only a proper perspective on death provides the true perspective on life. Living in the light of your death will help you to live wisely, freely and generously. It will give you a big heart and open hands, and enable you to relish all the small things of life in deeply profound ways. Death can teach you the meaning of mirth.
The author encourages us to take the one thing in the future that is certain - our death - and work backwards from that point into all the details and decisions and heartaches of our lives, and to think about them from the perspective of the end. It is the destination which makes sense of the journey. If we know for sure where we are heading, then we can know for sure what we need to do before we get there. Learn to find true joy and satisfaction in God's good gifts, and, in realizing your own smallness, see just how great God is.