How does Jesus' sacrifice assure our justification?

Justification is a core doctrine in Reformed theology, affirming that through Christ's atoning sacrifice, believers are declared righteous before God. Romans 5:1 states, 'Therefore being justified by faith, we have peace with God through our Lord Jesus Christ.' This justification is not through our works but is accomplished by Christ fulfilling the law entirely for us—'not one jot or tittle' was violated (Matthew 5:18). When believers rest in Jesus' sacrifice, they are assured that their sins are forgiven, and that His righteousness is imputed to them. Thus, they stand justified, free from condemnation, finding solace not in their own merits but in the perfect work of Christ.