Do you really think it was that easy?
The legend theory has been significantly refuted by many discoveries of modern archeology. These have conclusively shown that the four biographies of Christ were written within the lifetime of contemporaries of Christ. Some time ago Dr. William F. Albright, world-famous archaeologist now retired from Johns Hopkins University, said that there was no reason to believe that any of the Gospels were written later than A.D. 70. For a mere legend about Christ, in the form of the Gospel, to have gained the circulation and to have had the impact it had, without one shred of basis in fact, is incredible.
For this to have happened would be as fantastic as for someone in our own time to write a biography of the late John F. Kennedy and in it say he claimed to be God, to forgive people's sins, and to have risen from the dead. Such a story is so wild it would never get off the ground because there are still too many people around who knew Kennedy. The legend theory does not hold water in the light of the early date of the Gospel manuscripts.