Celsus had something to say about the originality of Christian myth:
"Is your belief based on 'fact' that this Jesus told in advance that he would rise again after his death? That your story includes his predictions of triumphing over the grave? Well let it be so. Let's assume for the present that he foretold his resurrection. Are you ignorant of the multitudes who have invented similar tales to lead the simple minded hearers astray? It is said that Zamolix, Pythagoras' servant convinced the Scythians that he had risen from the dead, having hidden himself away in a cave for several years, and what about Pythagoras himself in Italy - or Phamsinitus in Egypt? Now then, who else: What about Orpheus among the Odrysians, Protesilaus in Thessaly, and above all Heracles and Theseus? But quite apart from all these risings from the dead, we must look carefully at the question of the resurrection of the body as a possibility given to mortals. Doubtless you will freely admit that these stories are legends, even as they appear to me; but you will go on to say that your resurrection story, this climax to your tragedy, is believable and noble."
"Are these distinctive happenings unique to the Christians - and if so, how are they unique? Or are ours to be accounted myths and theirs believed? What reasons do the Christians give for the distinctiveness of their beliefs? In truth there is nothing at all unusual about what the Christians believe, except that they believe it to the exclusion of more comprehensive truths about God."
180CE