The “nakedness” in Gen. 3:7 is not the same as that mentioned in 2:25, where the husband and wife were naked but had nothing of which to be ashamed. As a consequence of sinning against God, they lost their covering of righteousness—their right standing before God, which they had at creation. God therefore had to provide a covering for them (see Isa. 61:10; Zech. 3:3,4; Rev. 3:18).
“The fig leaves used by Adam and Eve are called aprons, which cover only a part of the body and are not sufficient for a complete covering. The fig leaf is soft like velvet, and, under the heat of the sun, shrinks to about a quarter the size. These leaves are a type of self-righteousness. After Adam and Eve made the aprons they still hid themselves from God because they knew they were still naked in His sight. No amount of self-righteousness, or religion, or church attendance, or donations to worthy causes, or religious acts…is sufficient to hide the sins of the heart from God’s sight.” Walter Wilson
It is the light and heat of the Law of God that withers self-righteousness and exposes the shame of our sin.
Genesis 3:7 Then the eyes of both of them were opened, and they knew that they were naked; and they sewed fig leaves together and made themselves coverings.