Buy nothing you cannot use, is that a religion? Should it be?

One of my new year's goals was to get rid of belongings that I don't need.  What that also means that I shouldn't buy stuff I don't need.  Travel generally includes looking at the things people are selling.  There are a lot of hard sales pitchs to buy things.  I have decided it is my religion that doesn't allow me to buy things I don't need.  That's the first step towards reform, understanding the problem.