1. Imply that the Seven Principles are a creed.
2. Describe how your pet issue applies to the Seven Principles.
3. Talk about how any Unitarians who aren't in love with your pet issue are, by this reasoning, bad Unitarians, hyprocrites or just jerks.
4. Put an essay to that effect on the internet and/or make that argument incessantly to anyone who doesn't agree with you.
Though I am picking on Z, I'd like to stress that I have seen this all over the damn place with a huge variety of issues and it never ceases to bug me.
I really wish we didn't have the Seven Principles, because I'm tired of seeing them misused. They aren't a creed that can be used to prove people are bad Unitarians. They aren't a description of who we are.
There are many very fine churches that have creeds and/or scriptural authority that are always searching for new members. If you love having an objective standard to measure people with so much, it's been nice praying with you, you know where the door is.
tired and cranky.