Is there a "secret gospel" that tells the real story of Christianity? There's not just one "lost gospel"; there are many contenders to that title, most of them describing alternate versions of Jesus and his teachings. None of these "lost gospels" poses a real threat to Christian belief, but that doesn't stop us all from paying attention when a supposedly faith-shaking (and invariably discredited) document or discovery crops up, whether it's in the pages of a Dan Brown novel or a James Cameron documentary.

I bring this up because The Nation has a fascinating essay recounting the discovery of (and ensuing controversy over) the "secret version of the gospel of Mark", published in the 1970s by a Columbia University professor named Morton Smith. Smith claimed to have discovered an ancient letter from the church father Clement of Alexandria that confirmed the existence of an "evil version" of the gospel of Mark. This secret gospel recorded some extremely unorthodox teachings of Jesus—that salvation could be attained by sinning. It's bizarre, but it fit with the beliefs of the heretical Carpocratian sect that supposedly possessed this gospel.

Few of Smith's scholarly peers at the time actually believed the Secret Gospel of Mark to be a legitimate account of Jesus' teachings, and in fact most of the essay is about the interesting but confusing quest to figure out whether or not Smith forged the secret gospel himself. But reading the article, a single question kept repeating itself in my mind: why are we so fascinated by these false gospels and alternative versions of early Christianity? Why do we all tune in so breathlessly every time one of these controversial discoveries crops up? Why, two thousand years after Christianity's birth, do earnest but misguided scholars keep trying to find lost and secret texts that overturn Christian teaching?

Part of it is obviously good old-fashioned curiosity: this stuff is just interesting. Reading strange and false gospels helps us better understand the spiritual climate of the early church, and the sorts of religious ideas that Christianity was competing with. And certainly some people are motivated by a desire to see Christianity discredited. But I think there's something more.

I wonder if the very simplicity of the Christian Gospel is part of what drives this search for the secret, lost teachings of Jesus. There isn't any fundamental secret to Christianity: it's laid out plainly for anyone to read. Unlike many of the religions of Jesus' time (and some still today), Christianity has no hidden mysteries to learn; it's not an secretive club that you have to be initiated into. There's no advanced revelation reserved for just a few, no hidden doctrines you must earn the right to learn. And I think it's sometimes hard for us to believe that the key to salvation—the most sought-after secret in all of history—is so plainly advertised.

This is not to say we don't grow in spiritual maturity after we accept Christ; and it's not to dismiss the mystical tradition of the Christian church. But is it possible that one of the ways that the Gospel is a "stumbling block" is in the straightforward openness of its most central teaching?

Jesus Christ died and rose again, all to save us from our sin and restore us to a relationship with God. No mysteries, no secrets. It can't really be that simple, can it?