How do we know Christ's victory on the cross is sufficient?

The sufficiency of Christ's victory is demonstrated through His perfect obedience to the law and His sacrificial death on the cross. As described in Romans 8:3-4, God sent His Son in the likeness of sinful flesh and condemned sin in the flesh, fulfilling the law's requirements on behalf of His people. This victory ensures that there is now no condemnation for those who are in Christ Jesus (Romans 8:1). The cross represents a breach of the power of sin and death, establishing Christ not only as the sacrifice but also as the righteousness of His people, effectively nullifying any accusation from the enemy.