For me, the truth of Christianity hinges upon the reality of the resurrection. There are Christians who think that the resurrection is just a metaphor for the work that God can do in our lives. But I’m with Paul, who I think speaks for the early Christians in general when he says, “If Christ has not been raised, then our preaching is useless and so is your faith.” He later says that if the resurrection didn’t happen, “we (Christians) are to be pitied more than all men.” This is from 1 Corinthians 15
I guess there are really two important questions. One is, why do I believe the resurrection happened? And then, why do I think the resurrection matters?
As to why I believe (and more on why the resurrection matters tomorrow)–
I can’t explain the existence of the Christian church without the resurrection. From all we can tell, historically speaking, Jesus died a criminal’s death and his followers scattered and/or hid. They were an oppressed and powerless group of poor Jewish men and women under Roman rule. But many, if not all of the twelve disciples (excepting Judas, who killed himself), were executed because they continued to preach that Jesus was the Christ, the King, the Son of God. Peter went from a scared fisherman to a person who boldly proclaimed the universal need to know Jesus personally, and he claimed that the reason he preached was the resurrection.