How does sin affect humanity according to the Bible?

Romans 5:12 informs us that through one man's sin, death entered into the world, affecting all of humanity. This signifies that every person is born into spiritual death, separated from God due to the inherited sin nature from Adam. The implications are profound; without redemption through Christ, all are condemned. Understanding this doctrine helps us grasp the necessity of Christ's atoning work. It emphasizes that salvation is needed because all humans are inherently sinful and incapable of saving themselves.