Here are eight symptoms of false teaching:
1. There is an undeniable zeal in some teachers of error. Their “earnestness” makes many people think they must be right.
2. There is a great appearance of learning and theological knowledge. Many think that such clever and intellectual men must surely be safe to listen to.
3. There is a general tendency to completely free and independent thinking today. Many like to prove their independence of judgment by believing the newest ideas, which are nothing but novelties.
4. There is a wide-spread desire to appear kind, loving, and open-minded. Many seem half-ashamed to say that anybody can be wrong or is a false teacher.
5. There is always a portion of half-truth taught by modern false teachers. They are always using scriptural words and phrases, but with unscriptural meaning.
6. There is a public craving for a more sensational and entertaining worship. People are impatient with the more inward and invisible work of God within the hearts of men.
7. There is a superficial readiness all around to believe anyone who talks cleverly, lovingly and earnestly, forgetting that Satan often masquerades himself as an angel of light (2 Cor. 11:14).
8. There is a wide-spread ignorance among professing Christians. Every heretic who speaks well is surely believed, and anyone who doubts him is called narrow-minded and unloving.
~ Bishop J.C. Ryle
All these are especially symptomatic of our times. They have tremendous relevance for the church today. They tend to make the assaults of false doctrine today especially dangerous and make it even more important to say loudly, “Do not be carried away with strange doctrine!”
In The Hands of the Refiner 