Sometimes, setting rules is really helpful. Call them guidelines or self-imposed limits if you don’t like the idea of rules. But the fact is we do it all the time anyway. For example, we have a staff rule that male staff members or not to be in a house alone with a member of the opposite sex (apart from their spouse, etc).
But if you only ever discuss the rule and never discuss the reason behind it, two things are likely to happen.
1) Your rule will become a boasting point. It will become a rule in the bad anti-gospel sense. It will become something you are tempted to boast in before God and say, “Look! I never did that thing (that I self-imposed on myself!)”
2) It will become a tradition rather than a culture. That is, people will break the spirit of the law, and think nothing of it (e.g. going for a half-day walk in the bush with no-one else around – really isn’t much different to being alone in a house together).
So, have rules (because they help people understand the reasons and they do stop stupid decisions), but always talk about the reasons that make up the rule.