How do we know humanity is affected by original sin?

Original sin asserts that through Adam's fall, sin is inherited by all mankind, making us inherently corrupt and unable to please God through our works. The scriptures affirm this in Romans 5:12, where Paul explains that death came through Adam's sin, affecting not just Adam but all who descend from him. As a result, humans naturally rebel against God, culminating in a spiritual death that permeates our existence. Understanding this doctrine is crucial for recognizing our need for Divine grace through Christ, who redeems us from our fallen state.