It may seem like finding a purpose has become sort of a psychology buzz word for these days. The truth is, however, living for a purpose really will give your life meaning and structure. To have a purpose is a step beyond simply having a goal in life. A goal can be very materialistic, but a purpose will probably be altruistic instead. (In case you're unfamiliar with the word "altruistic," it means that you are concerned about the welfare of someone else and not just your own benefits.)
Really, you're not looking for "a" purpose, but for "your" purpose. The purpose that will make your life meaningful will be unique to you. It will be an expression of your innermost concerns and thoughts. It will also be the result of your experiences, because these have shaped the person you are, with your innermost thoughts and concerns.
Have you ever noticed how, in a group of people, each one will have something different that really gets them going? It might be concern for someone who is poor, or compassion for homeless animals, or possibly a love for the arts. By looking to these emotional hot spots, you can get an idea of what your purpose, or mission, in life really is.
Often a person's purpose is shaped by the experiences they had during childhood, whether these experiences were good or bad. For instance, if you were an abused child, you may feel a mission, or calling, to help other children who are abused, or perhaps you have a desire to counsel abusive adults. If your school experiences were positive, it might spur you to a purpose as a teacher. If caring neighbors gave you a ride to church, maybe you'll find your purpose in driving a church bus, or teaching Sunday School.
One thing that generally characterizes a purpose in life is that it usually helps people, or possibly animals. If your mission is to create beautiful music or art, ultimately you are being a blessing to your audience. If you only create beauty for your own enjoyment, you are likely to become self-centered and narrow. Reaching out to others as a benefactor is an essential part of a great purpose.
Your purpose, while it might be primarily a blessing to someone outside yourself, is likely to fulfill you as well. A great purpose will be something that you really love to do and that you feel well equipped to do. For instance, if children make you nervous, your mission in life will probably not involve teaching or caring for them. You might find helping the elderly or the handicapped to be extremely rewarding, however.
Your purpose in life may or may not be the thing that pays your bills. It's wonderful if a person can be involved in meaningful work while earning their income, but simply earning money to pay the family's bills is a great work in itself.
One idea to turn any occupation into more of a purpose for your life is to focus not just on the work and the paycheck, but also on the people who will be benefited by your work. If you are a mechanic, for instance, do your work well so the owner of the car will be blessed by your skill. Whether you work in a bank, restaurant, office, or factory, someone will get the benefit of the work you do. Focus on them while you work.