The coincidence of names, Jesus Christ and Great Cthulhu, is suggestive, but a linguistic accident. Much more convincing is the fact that Cthulhu is a god who died and yet lives, now and forever, and shall soon enough return in glory. Indeed, one of his (abortive) resurrections took place rather close to Easter. Both the return of Christ and the return of Cthulhu are eagerly awaited by hordes of worshippers who will do anything they can to hasten the day. Both are to be heralded by war, death and general chaos. Both are connected with astronomical prophecies - Cthulhu will return ``when the stars are right,'' while, according to Revelations, the Apocalypse should make astronomy a most interesting if confusing profession. Both will be preceded by unusual entities, Christ by the Beast and Cthulhu by Nyralthotep. Christ was preceded the first time by John the Baptist, who was probably yet another incarnation of the Crawling Chaos. Both will involve the elimination of death, in the Christian version by the resurrection for the Last Judgement.
Source:
http://cscs.umich.edu/~crshalizi/jesus-cthulhu.html