Without the resurrection, there is no Christianity. The resurrection proved once and for all that Jesus Christ is the Son of God. Every suffering Jesus went through on the way to the cross and at the cross was in exchange for the restoration of the dominion man lost. The Gospel of Salvation is the revelation of the Father’s love demonstrated in and through the substitutionary sacrifice of Jesus Christ. The object of that sacrifice is the entire creation, with a man being the central focus.
Jesus paid the price of justice; conquered the grave, sin, and death, and handed us the victory.
If Jesus had not resurrected, death wouldn’t have lost his power, because the last enemy to be destroyed is death.
When you receive the eternal life of God, you receive the power of resurrection. This means that for believers, even if our outward man perishes (we sleep), there is a hope of resurrection.
Because Jesus rose from the dead, the man obtained the power of resurrection.