In John 19:30, we see Jesus giving up his Spirit on the Cross after saying: " It is finished " . In Contemporary English Version, the words appear as " Everything is done" . So, by giving up his life on the Cross, Jesus completed the Mission of Salvation entrusted to him. But, Jesus rises again on the third day and we have St Paul saying that but for the Lord' s Resurrection, we would still remain sinful (1 Cor 15:17). One is therefore, intrigued if the salvific work of Jesus would have remained incomplete, had he not risen again. But then, why did Jesus say " Everything is done " just before he died on the cross ? My question therefore, is: Was the Resurrection of Jesus part and parcel of the Salvific Mission ? Inputs from scholars of any denomination are welcome.
The salvific mission of Christ having been completed by his death on the cross, without ever having sinned, the victory was won. Proof that he had been victorious at the point of death is that he was resurrected back to life. His perfect death defeated sin, death and the devil (who held the power of death):
"[Christ] also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil." Hebrews 2:14 A.V.
The resurrection of Christ was guaranteed with his mission being completed at the point of death on the cross. Nothing could prevent it! Death can only claim sinners, so because Jesus had not sinned and gave himself over to death, Death could not hold him. So, the completed mission included Christ's resurrection. Only if Christ had not completed the mission would his death have been just like any other human death - conquered by the grave. But the grave was conquered by Christ, as his resurrection proves.
All that was necessary for salvation to then be bestowed on sinners repentantly trusting in the finished work of Christ on the cross, was pregnant in his cry, "It is finished!"
The key word in the question seems to be 'mission'. Christ was on Earth to complete a mission that would bring salvation. Although the recipients of that salvation experience the start of a process after their justification, Christ's mission on Earth was completed at his death. He did no more to secure it as his work was finished with regard to his mission. His resurrection was part and parcel of a completed earthly mission.