Why so many "versions" of Christianity?

Here's a good question that is often asked of evangelical Christians like myself.

If Christianity is true, then why are there so many denominations, so many disagreements, and so many sects that split off from it?

The answer is maybe surprisingly simple. On the assumption that Christianity is true, where is the devil going to spend all his time trying to cause confusion, and what is he going to spend his effort on trying to counterfeit?

There's a reason why there's no market for counterfeit plastic. It's not worth anything. Counterfeiters counterfeit gold!