How do we know Christ's death conquered the devil?

In John 12:31, Jesus boldly states, 'Now shall the prince of this world be cast out.' This signifies the defeat of the devil's authority over God's people. Through His sacrifice, Christ not only satisfied divine justice but also rendered the devil powerless to accuse or reclaim those who belong to Him. The epistles, particularly 1 John, affirm that believers are kept from the evil one because of the blood of Christ. Thus, Christ’s death directly correlates to the spiritual victory over satanic forces, showing that His redemptive work has triumphed over evil.