I respectfully disagree. Gnosticism was very much a feature across many sects that otherwise differed, but it is also an underlying permanent temptation of Christianity and the post-Christendom world. It is not about one's spiritual journey, but rather a conviction that there is a divine secret to life that one can learn in order to belong to the "enlightened", i.e., gnostics. There are several versions today, but it is the same old desire to escape this material existence by denying its value in favor of a mental concept.