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

The doctrine of imputed righteousness refers to how Christ's perfect righteousness is credited to the believer's account when they are united with Him in faith. As stated in 2 Corinthians 5:21, 'For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.' This righteousness is both imputed, meaning it is legally declared over the believer, and imparted, which occurs through the new birth, granting them a new nature that desires holiness. Consequently, believers stand before God without sin, accepted in Christ's righteousness rather than their own flawed attempts.