However, everyone didn't seem to be able to understand "Be nice" so they made up a ton of reasons why he said this.
Eventually this was spun out of hand and one question led to another.
Eventually it started being used to give reason to biggotry. Such as hatred twords gays. When the real reason that these christians hate gays is simply because they are different from them.
It was mainly used to squeeze money from followers (similar to Sceintology). And to gain more followers the christians decided to smear other religons, like Saitanism, to have more followers and more money.
They did this by naming the guy they blamed everything on Saitan, putting their nonsense holidays on the same days as other holidays, and even taking over the holidays of other religons (like Christmas).
Today it is used for, the mental controll of the population of America, stealing money from it's followers, making hate laws (no gay rights), making yourself feel better than everyone else because you belive the story about the cosmic jewish zombie who is his own father, etc...
There are too many christians on the interent.
There are many different denominations of Christianity, and it is incredibly hard to estimate how many Christians there are in the United States because there is no common belief on what defines a Christian. The most liberal view of everyone who says they are a Christian being a Christian would place the figure around 75%, whereas the considerably more conservative belief that anyone outside your own denomination is not a Christian can place the figure as low as 0.1%.
Denominations sprout from the original idea of Christianity because some phrases from the bible contridict each other, and thus to harmonise this people say phrase A is literal whereas phrase B is symbolic. However, one group might say A is symbolic, but another might say B is symbolic. Thus, there are now hundreds of different denominations preaching slightly different versions of effectively the same source material.
Unfortunately, as Christianity is the 'big' religion of the Western World, it gets a lot of negative press. However, like all groups, Christianity has the best and worst among their number. The Christians who get the most press are the ones who give the stereotypical image of never doing anything wrong, and sitting on streets shout 'REPENT OR GO TO HELL', or something similarly pleasant.
However, many Christians - most, in fact - are decent people who just want the right to practice their own religion, like everyone else (or the right to NOT practice a religion, in the case of some).