Our dressing does show our personality. Society tends to judge a person by the she or he dresses. An example is a short dress or skirt, it tends to depict you are a carefree and fun loving person. A formal dress or a skirt that s below the knees shows that you are reserved.
Not for most people. I mean, if you see someone wearing Amish or Hassidic Jew outfits or something like that, it's pretty obvious. But the majority of people, you can't tell their religion by what they wear.