Excerpt from the book Holiness unto the Lord.
The first two clothes designers in history were Adam and God. They designed two coverings that were meant to accomplish the same purpose. One was by God himself, the right way. The other was by sinful man, the wrong way. In the book of Genesis, we find that after Adam and Eve committed the original sin they felt shame and sought to cover their nakedness. So this is the original form of clothing that sinful man used to clothe himself. “And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons.” (Genesis 3:7) These aprons that Adam and Eve made to cover themselves are what we would call loin cloths and are basically as much covering as a bikini would offer. So notice, this is the clothing choice of the original sinners. God confronts our parents over their sin and brings a curse upon the serpent, the woman and the earth. After this takes place God himself designs the clothes of Adam and Eve. “Unto Adam also and to his wife did the LORD God make coats of skins, and clothed them.” (Genesis 3:21) Adam and Eve chose to clothe to merely cover their private parts. God brought forth an animal and killed it as a sin offering for them. Then he took that and made it into what the Bible calls “coats of skins.” In other words, he made them clothing from the skin of the animal that was killed for their sins.
Let’s look more closely at the word “coats” in the Hebrew. The word in Hebrew is ku?tto?neth. It literally means to cover but was a specific garment that was worn. The Brown Driver-Briggs Hebrew Lexicon states that kuttoneth means “a long shirt-like garment, usually of linen.” The International Standard Bible Encyclopedia says, “Here the “coat” (Hebrew ketho?neth) was the ordinary “inner garment” worn by the Jew of the day, in which he did the work of the day (see Mat_24:18; Mar_13:16). It resembled the Roman “tunic,” corresponding most nearly to our “long shirt,” reaching below the knees always, and, in case it was designed for dress occasions, reaching almost to the ground.”
So God clothed Adam and Eve in a garment that truly covered their body. It was a shirt like garment that covered from the neck down to below the knees. Effectively God condemned wearing so little clothes as a loincloth or what we call a bikini. This was an immodest dress that exposed their bodies more than what was acceptable for sinners who were to live among sinners. We can see that a modest dress would be something that covers the body from the neck to below the knees, not revealing the breasts or the thighs and not so tight that it is revealing everything anyways.