Oneeno, it was a very good question, and I will try to give as good an answer.
First of all, I would like to say that for me religion is a very important thing. I do not treat it like something speculative or like some remote philosophical notion. I have had ample opportunities to observe people of different religions, I have changed my religion at one point in my life, and I really did see the way it influenced my whole life, and I was able to draw one conclusion, that is actually based upon facts - religion is a very powerful force, that influences every area of a person's life, despite the fact whether that person realizes that or not.
As for my definition of religion it is as follows - religion is a set of spiritual beliefs that you ACTIVELY practice in your life. The set of beliefs, characteristic of any given religion is shaped by the Deity, or Deities, worshipped in that religion. In any religion a Deity is a kind of immaculate personality, who sets down certain rules, that are in accordance with the kind of a personality the Deity is. Therefore, the ultimate goal of any religion is to reflect in your personality the personality of your Deity, as much as you possibly can, being human. On a more mundane level, a religion, your religion, the essence of your religion, is the guiding principle of your life, some kind of criterion, that helps you to make the right choices. And I also firmly believe that in this world religion exists in order to help people develop and grow.
I hope I have answered you question, and I hope I didn't make my answer sound too general.