The first human couple lived in the Garden of Eden, where they were meant to enjoy G‑d’s creation – including their own sensuality – innocently, as a means toward enhancing their awareness of G‑d and His goodness. However, they succumbed to the temptation to increase their self-awareness (as personified by the primordial snake) by eating the forbidden fruit of the Tree of Knowledge, and thereby lost their native innocence.
Modesty and Innocence
וַיִּהְיוּ שְׁנֵיהֶם עֲרוּמִּים הָאָדָם וְאִשְׁתּוֹ וְלֹא יִתְבֹּשָׁשׁוּ: (בראשית ב:כה)
The two of them were naked – the man and his wife – and felt no shame. Genesis 2:25

Adam and Eve did not possess any sense of self-centeredness before they ate the forbidden fruit. They therefore ate, for example, not in order to satisfy any lust for the taste of the food but to satisfy their hunger and enjoy the goodness G‑d had given them. Similarly, they engaged in marital relations not to satisfy any egocentric lust for sensual delight but to unite with each other, to enjoy the goodness G‑d had given them, and to have children.

It was only when they acquired the subjective knowledge of good and evil and its accompanying sense of self-centeredness – by eating the forbidden fruit – that they realized that sensuality could be something pursued for personal pleasure. Therefore, of all their naked limbs, they became ashamed first and foremost of their reproductive organs, and tried to lessen their power over human consciousness by keeping them covered.

It is thus through modesty in attire and behavior that we can regain our innate human innocence and elevate our sensual drives to the pristine purity of Adam and Eve’s in the Garden of Eden.1