you see, in the book of Genesis in the Hebrew, Christian, and (I think but idk) Islamic scriptures (it would likely have a different name), God created Adam and Eve. One day, Eve was tempted by the Devil, who had taken the form of a serpent, and bit an apple from the Tree of Knowledge of Good and Evil. This disobedience to God's explicit word, in which he said not to eat from that tree, brought the original sin into the world through Eve, and then Adam.