The purpose, well its to be surround by positives, to feel loved and to gain to inspiration to achieve for others and myself a better quality of life.
The reason you feel and think the way you do is lack of personal and social structure that make you realise what it is you are wanting to exist for. This is certainly generated through positive family, friends, work and relationships. Of which are crucial components in determining your role towards what you wish to exist for.
When the opposite occurs a sense of disconnect happens, as social beings by nature to feel connected with others and secure in knowing what the purpose, identity you have established for yourself is, is based upon the relationships established which create a determination towards what it is you wish to achieve in life.
The spark remains thus, this may be the singular reason why loneliness kills in the young, middle aged or elderly. The purpose to know what direction or who to give your time to give as well as receive love. We are designed to be social by nature when that is lacking life is lacking.
What other reason does religion or spirituality serve than to fill a social need to feel secure, to fill the emptiness when lonely, to have a belief in something when there is nothing else. Its the same with much of life, to have a good foundation, a good social structure is necessary to experience being needed, whether the individual chooses to do this out of love or duty depends on background. Its the same with money, job satisfaction etc, its used for immediate necessities that are the relationships and social aspect as well as the security to build your interests. When there isn't anything like that money means very little.