You have chosen to come to the earth plane for a purpose. At Spirit level there was one, or a number of issues, that your Karma identified as having to be balanced. Perhaps you came here to learn how to forgive, perhaps you came here to teach, perhaps you came here to learn how to give love to unloved orphans, etc., etc.
You can identify your purpose by what you do when you lose track of time. What you do when your passion takes over from your logic and you “fly” as you get “high” with passion and enthusiasm for the task at hand. This way you can find out what it is that you are here to give. When spontaneously you say “How can I help?”, when you have discovered your purpose, when you are helping others, when you feel passionate and time has no meaning, when you feel “high” on life, then know you are becoming part of God – as you Re-Member your purpose for coming as a Soul into a body on earth.