I’m almost done reading Irenaeus’s massive Against Heresies, an exhaustive refutation of the ancient heresy of Gnosticism, and a classic defense of orthodox Christian belief. It took about a year (though I deliberately took it slow). Some of it is quite tedious, and I often wondered if the pain was worth it. But, Gnosticism is alive and well, from the Gospel of Thomas, to Joseph Campbell. More surprisingly, there are actually Gnostic Catholic churches out there! Go get a copy of Irenaus–there could be a Gnostic right next door.