How do we know Jesus' work on the cross was effective?

The effectiveness of Christ's atoning work is assured through His resurrection, as stated in 1 Corinthians 15. The Apostle Paul highlights that if Christ had not been raised, then our faith would be in vain, and we would still be in our sins. Conversely, His resurrection affirms that the price for sin has been fully paid. Furthermore, Romans 1:4 links the resurrection to the declaration of Jesus as the Son of God, providing believers with concrete evidence of the sufficiency of His sacrifice. The empty tomb declares God's satisfaction with Jesus' sacrificial death and assures believers of their own future resurrection and eternal life.