We have assurance that Jesus conquered sin and death because He rose from the dead. By His Resurrection, Jesus proved to us that He finished the Work of Salvation that He promised He would complete. This is why Paul takes the time to remind the Corinthians (and us) of all of the accounts of Jesus’ Resurrection. He recalls how Jesus appeared to Cephas, also known as Peter; how Jesus appeared to the Twelve, who saw His wounds and witnessed Him eating; and how Jesus was seen by hundreds of others, on one occasion by over 500 people at once. There were many more who were able to testify during the time in which Paul wrote this letter that Jesus really rose from the dead.
It is important for us as believers in Christ to understand that Jesus really died and really rose. He did not just rise in spirit, or metaphorically. An examination of Scripture reveals evidence of real accounts of Jesus walking and talking in (the Resurrected) flesh after His Death and burial. Jesus’ physical Presence with the Disciples is what transforms them from being hopeless individuals afraid for their own lives into bold proclaimers of the Gospel who are energized in Spirit to go forth in Jesus’ Name.
Just as the Disciples are emboldened by the proof of Jesus’ Resurrection, we too can find courage in the assurance that our Savior gives us. Scripture records the evidence we need to see that everything Jesus said would happen to Him for our sake really did happen. He really came to Earth and foretold His Death, He really died to save us from our sin, and He really rose physically from the dead to prove that He conquered the grave and finished the Work of our Salvation. By His Resurrection, Jesus gives us proof in which to rejoice and evidence of His Work to share with others. Praise Our Savior for His glorious Resurrection!