How can christians say that the story of Jesus Christ is true when...?

Never mind the fable mongers. Anyone who had ever bothered to study the Christian religion and the Bible had discovered that there is nothing original in Christianity. It's a mixture of pagan rituals and plagiarized myths of other religious writings. If we are to accept religious stories as evidence, we will end up with contradictory evidence. There are many different religious stories from many different religious traditions, and these stories contradict each other... Religious stories cancel each other out. For every story there is another equally credible story that contradicts it, and contradictory evidence is self-defeating--it is like having no evidence at all!