Original sin

Original sin is a belief in Christianity that all people are born guilty of a bad thing they did not do. It is believed that when Adam and Eve were in the Garden of Eden (the very first people, according to the Bible) they made a bad choice by eating an apple from the tree of knowledge. This bad choice is called the "original sin". Because Adam and Eve were the first people, everyone that came after them was born into the world with this same bad choice already made for them, even though each individual person did not actually make that choice. This is why we say people are born with original sin.