The Gnostics of the first centuries CE didn't call themselves that, of course, but rather thought of themselves as Christians on the correct path, insisting that the Judeo-Christian doctrine arising from the Old Testament was based on a fundamental misunderstanding, and that the true God was not the creator of mankind nor of the material universe, but that this creator was a lesser god, an idea common in wisdom traditions. I'm not sure, on the face of it, how this would fit into a new or revived religion today as an alternative to Christianity.