How do we know Adam's sin is imputed to us?

The doctrine of imputation states that Adam's sin is charged to all his descendants. This is based on Romans 5:12, which clearly explains that through one man, sin entered the world and death spread to all people because all sinned in Adam. This imputation of sin means that Adam acted as a representative for all humanity; thus, when he sinned, all under him became guilty before God. This is a fundamental part of understanding our fallen nature and the need for redemption through Christ.