A: That's a good question that would have a pretty imprecise answer were it not for the teachings of The Urantia Book — The Urantia Book is all about answering that very question. So the best response would be to tell you to read the book and to decide for yourself, but instead I'll provide a condensed version.
First, you are a unique personality — there's never been nor ever will be another you. That's because personality is a divine and unique gift from the Father, yours being but one facet of a nearly infinite whole. This unique and divine personality is now being expressed in human form as yourself, but what you believe to be your personality and what others see as you aren't that unique and divine entity, what's being observed and experienced is your character interpreted as you.
Your personality is changeless, but your character will change as it becomes more in tune with your personality. It will appear that you mature and grow and develop wisdom during this life; still, this is only the bottom rung on a ladder of progress stretching to eternity. Your personality is so rich in endowment that unfathomable time is required for your character to develop its full potential in expressing that true personality.
Here on earth, you are also a product of your environment and of both biological and cultural heredity. If your biological heredity is faulty it will be pretty difficult to overcome those shortcomings in this life but you'll be provided ample opportunity to do so in what's to come after this life is over. Environmental and cultural hereditary defects can be overcome by exercising your character and another God given attribute, free will. If you choose to let the circumstances of life dominate you then you will have hardly exercised your free will at all, exhibiting instead character weakness that needs to be strengthened. If you invoke your free will in overcoming hardship and privation to build a life of accomplishment and joy character growth will result.
Your character is the result of the choices and decisions you make; how you think about and treat yourself, other individuals and the world around you; honesty, loyalty, truthfulness, responsibility; your attitude toward life and your place in the cosmos.
So, you are a nearly infinite potential being expressed through a developing finite character. You have the aid and guidance of unseen spirit forces to assist and you have the influence of the Holy Spirit and of the Spirit of Truth to help you with the challenging decisions life requires you to make. You're a tadpole striving to become a frog which will eventually transform into a prince as long as you keep the goal in mind and continually strive for God-likeness. God is the home to which we all yearn to return.
Please see our topical study on Personality for a lot more information about who you are."