If Jesus were not raised from the dead then we could not have assurance that the price of our sins has been paid. Christ was the perfect Lamb offered in our place, the single sufficient sacrifice for the sins of all who would believe on Him. His death provided our only way of being accepted by God. Without it we are doomed. Christ’s resurrection is the assurance that this was completed, and that sin and its resulting death (physical and spiritual) was fully overthrown. What assurance could we have that the work promised had been done through the means of the cross if He did not rise to verify it?