Who Are You?

I'm reading the book of Acts right now. I thought it was somewhat appropriate since I'm beginning my missionary journey. I do have to wonder though, who will I be?
Will I be Paul, whose zeal for Christ was immeasurable? Will I be like Barnabas, showing compassion and making a difference, or will I be like John Mark and leave when the situation gets to rough for comfort?
I believe that every man and every woman is faced with this same question. Just as I must answer, so must you. Who are you?