Theoretically speaking here, Nothing found in the literal Word of God should ever deceive a true Follower of Christ. And that Truth has been evident for the past 2,000 years. But, within that past 2,000 years, and even more recent within the last 500 and 200 years, Doctrines not found discussed by Christ, the Apostles, even the Church Fathers have been popping up left and right. And then more recent, within the past 50 years, we've seen Doctrines that dealt with Wealth, Healing, Name it Claim it, the revived Grace Message [License to Sin/God created 2 types of people, 1 for Heaven, 1 for Hell]. And most recently, the Seeker Friendly Movement has swarmed to the surface.
Now, those ^ Movements have been extremely damaging.
Grant it, we have the New Age Movements, the Universal Love Movement, and Scientology, but those fade and you don't hear of them for awhile.
Then we have Mormonism and Jehova Witnesses, but they don't recruit well and are only continuing because people are born into it and remain and have children and the cycle continues.
But no doubt, there is a Movement coming, that will shake the Core and Thin the Ranks. Time will tell, but I believe we won't have to wait very long for it to birth itself onto the scene.