The apostles believed Jesus was the Son of God or Messiah and as a result from their interpretation of Scripture, resurrection was the only explanation they could offer themselves after he died. Of course, the idea of zombie Jesus came along afterward when other gullible followers understand bodily resurrection to occur on Earth in their day rather than at the end of time as Pharisaic Judaism traditionally taught.
He who loves God cannot endeavour that God should love him in return - Baruch Spinoza
