For me personally, I find that my faith, which calls for self reflection, personal acts, with an emphasis on educating yourself to the world around you are the biggest draws. However my faith also does not demand you prostrate yourself to Ahura Mazda. In fact, quite the opposite. It wants you to prove your devotion through actions, rather than words. Working to make the world a better place is the highest calling any Zoroastrian can get, and it is this exact sense of the Free Will to choose how you want to make the world better is what makes it even more enthralling.