Do you have a sense of where you want to take your career? For example, you may ultimately want to practice academic medicine, which would give you an opportunity to see patients in a clinical setting, conduct research to help the patients you see, and teach the next generation of lifelong learners. You may want to focus purely on research because you believe that is where you will have the greatest beneficial impact on the largest number of people. Or you may wish to do something else altogether. I would think deeply about where you want to be one year from now, five years from now, and beyond. I would then relate my prior clinical, research, classroom and life experiences to that goal--trying to show, rather than tell, the reader how and why that came to be your goal.