Your medical school personal statement needs to sell. Every single word has to sell your reader and answer the question: "Is it worth my time to read one more word of this essay?" To be persuasive is to sell your reader on your next sentence, your next paragraph, your next idea of your medical school essay.
Once you have a good amount of information and several personal statement samples to reference you can then sit down and begin to put down your thoughts for your statement. Don't try to write your personal statement after only viewing one sample as this may inadvertently lead you to create a carbon copy of what you are looking at. By writing down your thoughts first you will be able to ensure that you are getting a good mix of ideas and inspirations from the various personal statement samples you like.