The original sin is a term used to refer to the first act of sin committed by Adam and Eve that led to the fall of man.
A long time ago, after God had created everything, he created man in His own image. Now God Himself planted a garden full of fruitful trees and animals around a great river in a place called Eden. Now in the middle of the garden, God put two trees, the tree of life and the tree of the knowledge of good and evil. Now God took Adam, the man He had created, and put him in the garden; and having put him there, He commanded Adam, saying, “You may surely eat of every tree of the garden, 17 but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die (Genesis 2:13-17).”
Later, God created a woman for Adam and she lived with him in the garden. Now Adam obeyed God’s word until one day, his wife made him disobey. It happened that the devil deceived the woman to eat the forbidden fruit, and after having eaten it, she took some and brought it to Adam. Then Adam listened to his wife, took the forbidden fruit, and ate it to disobey God’s word.
Christians who have carefully read through John 14:15 and 1 John 5:7 understand that Adam’s action indicated that he loved his wife more than God; for he listened to his wife to disobey the command of God.
God’s response (Genesis 3:14-19)
God was much displeased and said to them:
14 The Lord God said to the serpent, “Because you have done this, cursed are you above all livestock and above all beasts of the field; on your belly you shall go, and dust you shall eat all the days of your life. 15 I will put enmity between you and the woman, and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel.”
16 To the woman he said, “I will surely multiply your pain in childbearing; in pain you shall bring forth children.Your desire shall be contrary to your husband, but he shall rule over you.”
When it got to Adam, God made it clear to Adam that he, Adam, has chosen his wife over Him, God. God said to Adam, “Because you have listened to the voice of your wife and have eaten of the tree of which I commanded you, ‘You shall not eat of it,’ cursed is the ground because of you; in pain you shall eat of it all the days of your life; 18 thorns and thistles it shall bring forth for you; and you shall eat the plants of the field. 19 By the sweat of your face you shall eat bread, till you return to the ground, for out of it you were taken; for you are dust, and to dust you shall return.;” (Genesis 3:17-19 ESV)