Our joy rests on the willing sufferings of Christ. Jesus has rescued us from the foulest form of suffering, that we could be cast away from and separated from God, that we would have no way to atone for our sin, that we have no way of being healed of the abuse and shame we suffered. It was His joy to endure the cross, pain, suffering trial and shame so that He can bring us everlasting joy in the midst of temporal suffering and pain.