Not the same because Xenu is not the primary basis on which the religion of scientology exists today for the majority of its members.
From Wiki on Xenu:
Senior members of the Church of Scientology have several times publicly denied or
minimized the importance of the Xenu story, but others have admitted its existence. In a BBC Panorama program that aired on May 14, 2007, senior Scientologist Tommy Davis interrupted when celebrity members are asked about Xenu, saying:
"None of us know what you're talking about. It's loony. It's weird."...
http://en.wikipedia.org/wiki/Xenu
So you can't compare the fact that the resurrection is whole essence and the reason for the existence of Christianity to Xenu who senior scientology members have denied or minimized.