"Say an organization (religion, cult, club, whatever) wants 10% of your income for whatever reason, and a portion of your free time every week. Its a cause you believe in, and you can afford it without negatively affecting your life or that of your family. Clearly not a stupid choice to be part of this. How about a group that wants a significant portion of your money, soaks up copious amounts of your free time, and is trying to convince you that you should have no contact with those outside of the group aside from attempting to convert them? Sounds like a bad choice to me." Sounds like a very arbitrary line. When exactly does it go from being a religion to a cult? 20% of income? 50%? 20% of your free time? 50%? That's why no one can define a cult because the definition itself is arbitrary and any logically definition would surely include many main stream religious denominations.