"The way I see it, fashion is a uniform. As a unique individual, I was never a fan of those."
These words are my own. I have never been big on dress codes, as I see them as imaginary rules set by a bunch of miserable, elitist killjoys. However, while diversity is a good thing, the Bible does set some rules regarding clothing.
The first rule, of course, is that it must be worn. Nudity is seen as a precious thing. It is not for just anyone to see, but primarily must be revealed only to one's spouse. Of course, there are exceptions. In the presence of a medical professional, for example, it can be appropriate, even necessary. However, exceptions are few and far between.
This goes back to Genesis. Originally, Adam and Eve were naked, and they felt no shame. But when they sinned, they tried to cover themselves up. Awareness of sin brought a fear of visible nudity. Even unbelievers typically wear clothes, and it's interesting to note that some missionaries report that upon believing the Gospel, some nudist people ask for clothes.
When Adam and Eve initially tried to hide their nudity, God rejected their efforts. Rather than just letting them make their own clothes out of leaves, God killed some animals and made clothes from their skins. This is a very early typology. God was effectively saying "I, and I alone, can cover your sin, but it does require a blood offering". Thus, nudity represents shame and sin, whereas clothing reflects God's atonement for it.
Thus, clothing is necessary, but it is not necessarily sufficient. The Bible does outline a few rules on top of that. This falls into two categories: Don't tempt another person to sin, and don't show off.
In Luke 17:1, for example, Jesus says it is inevitable that temptation will come, but He pronounces a curse upon those through whom it comes. For me as a man, even a walk down the street is dangerous. Why? Because there's a very high chance that a young woman will be dressed in such a way that's specifically designed to make me want her. So I'll stay home, turn on the TV, but there's another one trying to sell me an aftershave or a razor. I log on, click a few things on the internet, and ding; one more girl wearing far less than she should be, all because some billionaire wants another fiver from me.
Now, to be clear, although such people are in the wrong for tempting others, each person is responsible for their own sin. As Job says, "I have made a covenant with my eyes; Why then should I look upon a young woman?" (Job 31:1). When a man looks upon a woman with lust, it doesn't matter what she's wearing, it is he who has committed adultery with her in his heart. However, all of us, men and women, have a responsibility to not cause each other to stumble.
But it's not all about temptation; it's also about pride. In many cultures, appearance is a statement of status. "I'm rich, I'm important, I'm holier than thou." These are things which ought not concern us. Why? Because it is not ourselves we're trying to draw attention to. It is our God.
The long and short of it is that a Christian is supposed to dress sensibly. Our goal is to avoid offending anyone, be they an unbeliever or a fellow servant of Christ. Nor are we supposed to boast of our riches, which would be better spent on essentials and charity than luxury. The way we dress reflects the way we worship. Let us therefore dress in a manner fitting for children of God.