I'm a Quaker or Friend of Jesus and we live by a series of "testimonies" and one of those is the Testimony of Simplicity. This is drawn from Jesus' teaching and traditional Friends in the Midwest practice it with plain dress and a lifestyle that resembles the disappeared-Shakers or more liberal Amish.
In California it is sporadic in practice. If we really practiced it, we would be truly counter-culture as the anti-materialistic message is certainly at odds with the U.S. culture. Nonetheless, people in my meeting do try to live by this testimony. We especially work to not buy goods made with slave labor, no Walmart, etc. We also challenge one another to live more simply and that means with less stuff.
There is another Friends' testimony: the Testimony of Truth. The scripture that is often referenced is Matthew 5: 33-37 (from the Message): "And don't say anthing you don't mean. This counsel is embedded deep in our traditions. You only make things worse when you lay down a smoke screen of pious talk, saying, 'I'll pray for you,' and never doing it, or saying 'God be with you,' and not meaning it. You don't make your words true by embellishing them with religious lace. In making your speech sound more religious, it becomes less true. Just say 'yes' and 'no.' When you manipulate words to get your own way, you go wrong."
This is reinforcing my commitment to clean up my bad habits of saying, "I'll pray for you." Or "I'll try." This latter phrase creates an expectation that you might actually try, and yet if we are truthful with ourselves, our hearts are saying no.