We have seen this first hand in conservative Anabaptist groups where a desire to "be not conformed to this world" (Romans 12:2) has morphed into a very rigid set of rules to prove one is not conformed to the world, while at the same time tending to create distinctions not just between the church and the world but just as often distinctions between the church and other parts of the church.
Simon Fry takes aim at this in his new series on Non-conformity. The second post in the series, Nonconformity- (part 2) When Does Transformation Happen?, which looks at non-conformity from a conservative Anabaptist perspective, does a deep dive on how Romans 12:2 and non-conformity are understood in that community. Simon's main point can be summarized in this one sentence:
Though we might not hear it emphasized, transformation must happen first; or nonconformity is worthless.In other words, or as I might put it, regeneration must precede genuine sanctification. Genuine sanctification includes external signs of a non-conformity to the world but it starts with and is primarily a renewal of the mind, heart and affections away from the things of the world and toward the things of God. I can put a young woman in a homemade yoke-style dress with sleeves to the wrist and hem to the ankles but if she is harboring gossip and slander in her unregenerate heart, she is still conformed to the world no matter what she looks like.
That is not to suggest that there is no place for non-conformity. The Bible teaches modesty so a woman who tells me she is a Christian while intentionally dressing provocatively might get a raised eyebrow. An every-week-church-attending deacon at a conservative church who regularly cheats his customers in business likewise raises questions. I think brothers should be respectable in their communities and honest in their business dealings, sisters should dress modestly and submit to their husbands but only as a response to regeneration, not as a substitute for it.
Check out Simon's post, it is typical for him in being well reasoned, Scripturally based and thoughtful. Also check out the comments, there is some good back and forth going on there as well. Ultimately our Gospel priority is to see the whole man changed and not just the wardrobe.