Life purpose, uhm, maybe I am here because I may help a person change the world?  No, we are here because we have different missions in life.  We are here because of some specific plan that God designed for us to fulfilled.  We are here for His purpose.  Being dead is the privilege  of those who are used in suffering, maltreated, abused, tired, and weary.  They would not have to think of anything, they will not feel any pain.  They said that if we die, we will go to heaven or hell, the only way to eternity is to accept Jesus as our Lord and Savior.  There is no other way than Him.  And I may suggest that you read the Purpose Driven Life of Rick Warren.  I do not have, but I wish I could read it sometime.