How do we know Christ's afflictions were sufficient for our salvation?

The sufficiency of Christ's afflictions is affirmed in His declaration, 'It is finished' (John 19:30). This statement indicates that all necessary conditions for redemption were fulfilled on the cross. The perfect sinless nature of Christ and the depth of His suffering satisfied God's justice and secured salvation for His people. Paul clarifies in Colossians 1:24 that the sufferings believers experience do not add to Christ's redemptive work but instead reflect their own participation in His afflictions as part of the church, His body. Thus, believers are assured that they cannot add to what has already been accomplished in Christ.