When believers struggle to be settled about the once-for-all nature of their justification before God, they must look on the crucified and risen One by faith. Jesus was justified before God in His resurrection so that we might be justified by faith in the risen and victorious Christ.
We sometimes fail to meditate deeply enough on all that the resurrection of Jesus means for believers. The resurrection was not simply the evidence that the sacrifice of Christ was accepted by God–though it certainly bears witness to that truth. The resurrection was also not merely the prefiguration of the resurrection of those savingly united to Jesus–though it secures and anticipates the resurrection of the just on the last day. The resurrection of Jesus is essentially the cancellation of the condemnation of sin represented by the sentence of death–the justification of Jesus as the representative of His people.
Geehardus Vos, in The Pauline Eschatology, explained this principle so well when he wrote,
“Christ’s resurrection was the de facto declaration of God in regard to his being just. His quickening bears in itself the testimony of his justification. God, through suspending the forces of death operating on Him, declared that the ultimate, the supreme consequence of sin had reached its termination. In other words, resurrection had annulled the sentence of condemnation.”