Life is the most precious gift because without life we will not be able to receive anything else, or experience some the great moments of life. When we became aware of the life we have received and how valuable it is for us, we rejoice and try to make our life the best we can. This is physical life, and we know that it will not last forever, but we still appreciate every minute we have.
When Jesus said: I am the life of the World, with those words He means more than physical life. He wants us to ponder about the spiritual life, a life that does a lot more than the physical one, a life that does not end, and a life that starts with us while we live this life.
The life that Jesus proclaims is not something for a specific group, but He is the life of all for the whole world. That is the reason why we eager to share our faith with others, that they may also participate in the life we have. There is a big difference between the world without the life that Jesus gives, and the world with Jesus. And it is a big difference between a person full of the divine life and others without it. We unconscientiously wish for and, desire this life because within us is a thirst for eternity. We want to life forever; the ancient world shows that building monuments to remember those who lived in that time, somehow live thru them forever. In our time is more to leave a legacy that will mark our presence in this world. All those desires and intents are legitimate but do not accomplish, or fulfill our desire for eternity.
If ones wishes to live forever they need to embrace the life that Jesus offers, this life is not other than Jesus himself. With him we are alive, with a life that transcends the physical world. Jesus offers a life that overcomes even death itself: “I am the resurrection and the life; whoever believes in me, even if he dies, will live, and everyone who lives and believes in me will never die.