We are all searching. We are searching for what it means to be a live and how we can best live our lives. It is a hard question to answer. What should the purpose of your life be, and, how should you live your life to attain that purpose in the appropriate way?
Ravi Zacharias, a Christian Apologist, splits the meaning of life into four categories: wonder, truth, love, and security. As children we find meaning in wonder. The world is filled with enchantment and as a child one does not ask why something is the way it is. As a child a person can be satisfied and find meaning in mere wonderment of the world. As youth, mere wonderment does not bring meaning to a persons' life. Youth seek truth, because to only be amazed by the world is not enough, understanding is also needed. During the middle years of life meaning can be gained from finding love and in old age meaning is found in security. Once the truth is known, love will fill the longing a person has for meaning. In old age a person can gain meaning from security, security in knowing that once life is over on earth it continues in heaven. Ravi Zacharias then connects the four stages of meaning to God. A child finds wonderment in God. God gives the youth truth. God fills the middle years of life with love. Security is gained from God's promise of an afterlife. Thus, according the Ravi Zacharias, in order to attain the meaning of life, a person must believe in and follow the Christian God.
I generally agree with Ravi Zacharias' assertion that meaning of life can be found through God giving meaning to our lives by giving us wonder, truth, love, and security. However, the way it is broken down into a sequence that must be followed in order to attain purpose to life seems too scientific. To break down life sequentially and say that at each stage of life you attain meaning from a certain thing is too formulaic. I do not believe that life is that sequential, it has to work up to one greater meaning or purpose. To say in old age the only thing that can give you meaning is security does not make sense and I think any elderly person would agree with that. If Ravi Zacharias had made the argument that one attains purpose or meaning from life by finding wonderment, truth, love, and security at the same time I would find that more believable. The meaning of life cannot be attained through a specific formula of attaining a certain thing at a specific stage of life; it is just too sequential.
Dr. William Lane Craig, a professor of philosophy at the Talbot School of Theology, best described what I personally believe the meaning or purpose of life to be. According to Dr. William Lane Craig if God and immortality do not exist then life becomes meaningless. "There is no God, and there is no immorality. And what is the consequence of this? It means that life itself is absurd. It means that life we have is without ultimate significance, value, or purpose (5)." William Lane Craig believes that if there is no God, there is no immortality. Without immorality everything that one does during life becomes meaningless. It does not matter if a person does numerous good things while they are a live, because everyone has the same end. Whether someone lives a life like Hitler or Mother Theresa does not matter, if there is no immortality, once you die that is the end. Actions during life do not matter when there is no immortality, because a person is not working toward anything, but death. "Mankind is a doomed race in a dying universe. Because the human race will eventually cease to exist, it makes no ultimate difference whether it ever did exist (5)." Dr. William Lane Craig makes the argument that no matter what in the end everything dies and thus life has no meaning if there is no afterlife. He goes on to say that not only does man need immortality to gain meaning from life; he also needs God.
"In a world without God, there can be no objective right and wrong, only our culturally and personally relative, subjective judgments. This means that it is impossible to condemn war, oppression, or crime as evil. Nor can one praise brotherhood, equality and love as good. For in a universe without God, good and evil do not exist—there is only the bare valueless fact of existence, and there is no one to say you are right and I am wrong (7)."
I tend to agree with Dr. William Lane Craig's statement about right and wrong becoming subjective when there is no God. If there is no higher power or good then it is impossible to discern what is good from bad and if you cannot discern good from bad it is difficult to fulfill any sort of purpose that life is meant for. If everything is subjectively right or wrong there is no way for a person to strive for good. Thus, if there is nothing a person is trying to live up to, then everything in life becomes pointless. Dr. William Lane Craig also points out that meaning or purpose cannot be attained from just immortality or just God. They are interdependent. Purpose is gained from knowing that one will continue on after death and that actions on earth factor in to where one will continue on into eternity. By following God one can attain their full potential in life.

Ms. 8.6 of 10 on the basis of 1143 Review.