The words 'Original Sin' are familiar ones, but they are not found in the Bible. The expression refers to the first sin ever committed – 'the' original sin. It was introduced by Adam and Eve through a wilful act of disobedience against the revealed will of God. Their sin had a global effect contaminating everything created by God. (The full account can be read in Genesis 3.)
Personal Responsibility
As a result of Adam and Eve's sin, all of us suffer the consequences of their behaviour as distinct from (1) inheriting their sin or (2) being punished for what they did. The prophet Ezekiel makes clear that each person is responsible for his own sin. 'The soul who sins is the one who will die. The son will not share the guilt of the father, nor will the father share the guilt of the son. The righteousness of the righteous man will be credited to him, and the wickedness of the wicked will be charged against him.' (Ezekiel 18:20)
While each of us must bear personal responsibility for our own sins, we still have to live with the consequences of what Adam and Eve did. Let me explain this by way of an illustration. A nuclear explosion occurred in Russia in the late 1980s. The 'fall out' affected everyone living in that region. Innocent people suffered the consequences of something they were not responsible for.
We Suffer the Consequences, Not the Guilt
In the same way, the sin of Adam and Eve has a 'fall out' effect on us, their descendants. For example, we are born with what is called 'a fallen nature', that is a nature prone to sin. Wherever we look in our world, we see the evidence that our planet is inhabited by people who sin. Whether people are living in what we describe as 'a primitive culture' or in an advanced society, sin is present. People behave in evil ways. The history of mankind is stained with many acts of evil: wars, injustice, corruption, sexual abuse, etc. Why has there always been evil in every century? Though we are separated from people who lived in the past, and they from us, yet a common denominator links us together. It is undeniable - we all possess a fallen nature. We are indeed the children of Adam.
Though we have a fallen nature, we are not born separated from God. No. Reflecting upon his life, the Apostle Paul says there was a time in his life when 'I was alive.' (Romans 7:9) He is referring to that age of innocence before personal sin separated him from God. But when sin entered his life, he died spiritually.
We are like our ancestor Adam. We, too, have made a bad choice.