The Shroud of Turin is often held up as relic of Christ, even though there's no evidence that it actually was the burial shroud of Christ, and there's very good evidence to suggest that it was a middle-ages work of art.
There's a modern day story spread that Darwin recanted on his deathbed, something that is completely made up. The person in question who Darwin was supposed to have recanted to didn't visit Darwin during his final days.
Many statues, mainly of the Virgin Mary, have been made to weep in order to appear miraculous.
Faith healers use a variety of deceptive techniques as part of their performances.
A group of people committed suicide, convinced that by doing so there was a spaceship behind the comet Hale Bopp, where their suicide was casting off bodies to take them to the next level.
There are many people who are rewriting history to make United States a Christian nation, despite the secular nature of the origins of the country.
I could go on with examples, but it should be clear by now. These are the kinds of behaviours that we know people are capable of, especially when it comes to religious belief. For us to look back at the accounts of the New Testament and early Christianity, is the only good explanation that Jesus really was who he is made out to be in the gospels?