Philosophy is an insight to humanity or a humanistic study. It is humanistic because it deals with the beliefs of rational (human) beings. Philosophy differs from other disciplines because it is one that is in search of a subject matter, whereas other disciplines have an assigned subject matter. Philosophy is a way of examining ideas. In order to think philosophically about something it has to meet certain requirements. It is not very wise to try and think about something such as your dresser draw in a philosophical manner, this will not yield very fruitful results. The subject has to be rich, cohesive, complex, and significant in order to be thought about in this manner. The meaning of life meets these requirements. .
Most people question the meaning of life at some point in their life. There are three different questions that a rational being may ask that would motivate him or her to search for the meaning of life. The first type of question is a cosmological question, such as, why does the universe exist, why is there something rather than nothing, and is there some plan for the universe? Concerns relevant to these questions are religion and God. Answers to cosmological questions that a philosopher would find satisfying have to do with a supreme being or a concept of God. A dismissive response could be offered here, but I do not think that it would be a very satisfying approach to this type of question. .
Another type of question that could provide motivation in ones search for the meaning of life is an impersonal or omnipersonal question. Question's that considered impersonal are asking things like, why do humans exist, do humans exist for some purpose, and if so, what is that purpose? Relevant concerns with this kind of question are God and ethics. Humans are significant when approaching impersonal questions. An answer that would be satisfying in this area is that humans exist to serve God.