Non-Christian thought is a bottomless pit, and one can easily consume himself in its study. Nevertheless, while it is better to comprehend the truth, it is foolhardy to remain ignorant of our enemies. Towards that end, I’ve found the following to be an extremely useful guide when comparing esoteric traditions like Freemasonry, Theosophy, the New Age movement, Kabbalahism, Mormonism, etc. From The Western Esoteric Traditions, by Nicholas Goodrick-Clarke:
Taking the Renaissance concordance of Neoplatonism, Hermeticism, and Kabbalah, along with astrology, alchemy, and magic, Faivre deduced six fundamental characteristics of esoteric spirituality. The first four of these he described as intrinsic in the sense of all being necessary for a spirituality to be defined as esoteric. To these he added two more characteristics, which although not necessary, are frequently found together with the others in esoteric traditions.