The only valid answer I can think of is that this new stuff is just the same old lies and deceptions repackaged. The Bible is God's complete and exhaustive manual on how to maintain a good Christian life. There is no need for us to go on a quest for higher understanding. Any difficulty on the part of man's understanding rests with his inability to just except the boring truth. He told this lie to Adam and Eve, and we all know what happened to them.
Christian apologists spend a huge amount of time refuting every new teaching that springs up.
Because the devil is continually on the job, erroneous doctrine tends to encroach like jungle vines. In the early Church, every time Paul turned around, he had to combat some new falsehood that had crept into the body of Christ. Because there's an unlimited number of false doctrines circulating in the world, rather than reading up on what everyone else believes, I think it's a far easier task for a person to focus on what he should believe concerning God's Kingdom. In many cases heretical doctrine can be very difficult to detect. A lie can come wrapped in 95 percent truth and still be a lie.