How do we know that Christ's mediation is effective?

Christ's effectiveness as a mediator is rooted in His perfect nature and the complete and sufficient sacrifice He made on behalf of sinners. The Bible states that every case He mediates is assuredly resolved due to His perfect righteousness. Unlike human mediators who may succeed or fail, Christ's mediation guarantees that all who come to Him in faith are justified before God. This assurance is based on His successful atonement for sin, evidenced by His resurrection and the unchanging promise of God in Scriptures that those who trust in Christ are accepted and accounted righteous.