How do we know Christ's righteousness is imputed to believers?

The imputation of Christ's righteousness to believers is foundational to the doctrine of justification by faith. This is articulated in Isaiah 50:5-6, where it highlights Jesus' obedience to God, even unto death. His perfect life and righteousness are credited to the sinner's account, thus changing their standing before God from guilty to justified. This is further affirmed in Romans 4:3, where Paul explains that Abraham's faith was counted as righteousness. For the believer, this imputed righteousness means they stand before God not by their works, but by the grace freely given to them through faith in Christ. As a result, they can approach God without shame, clothed in the perfect righteousness of Christ.