What Is Gnosticism?

I've always just thought that Gnosticism was basically the idea that people who are involved in a Gnostic mindset have. I've got the secret knowledge, and my group has a secret knowledge and we know something that you don't know. That seems to me like that would be very toxic if that got into Christianity because Christianity needs to scale for people of every mental capacity and every age. But what else is there about Gnosticism? Are there people who are holding views that could roughly be called Gnosticism that are within traditional Christianity?"Yeah, well I mean, it's definitely something that's been with the church since the beginning," he says. "And again, I think