Christian naturism
In the Book of Genesis, Adam and Eve were living in the Garden of Eden as 'man and wife' . They ate the fruit not allowed by God, after being talked into it by the devil in the form of a snake. Then their eyes were opened, and they knew that they were naked. So, they gathered fig leaves to be used as simple clothing to cover their sexual organs. These became lacking very quickly, and Adam and Eve hid themselves from God in the trees.