The Bible affirms that all people are sinners through the doctrine of original sin and the universal nature of sin (Romans 5:12).
The assertion that all people are sinners is supported by the doctrine of original sin, which teaches that sin entered the world through one man, Adam, and thus death spread to all mankind because all sinned (Romans 5:12). Since Adam, every human being is born with a sinful nature, leading to acts of sin throughout their lives. Hence, the universal condition of humanity is one of sinfulness, highlighting our need for redemption through Christ.
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