Problem is, many people jump up and down and rant and rave at "false teachers" when they simply subscribe to a different version of theology. I have seen to genuine beleivers accuse each other of being a false teacher simply based on timing of rapture.
Thing is we cant get it all right, no one has it 100% correct. False teachers we are warned about are the ones who will take us away from God by following spirits other than Holy Spirit and falling for thier lies, we see such teachers embrace all kinds of occult and blasphemies and pass them on as holy. Then there are those who give prophecy, or messages from God which never happen, these are dangerous people to follow as they are false.
Good example of false teachers, Benny Hinn, he comes out with some strange things, such as saying Jesus will appear on stage, give out prophecy and messages from God which never happen or come true, he fails to repent. The powers he has is not Holy Spirit power, but denomic power.
Todd Bentley, disgraced TV evangelist who has been banned from entering the UK based on him kicking people in the head because GOd told him to do it to heal them. He gets messages from an "angel from God", he has out of body experiences and is obviously under influence of Kundalindi. came to fame with his Fire Ministry, where he passes on Holy Fire to anyone who wants it, but it is really demonic, as he got this from his angel, which I would not be surprised if it turned out to be satan himself. He is also another one who claims Jesus will appear with him, its bad enough claiming he has his angel standing next to him that only he can see, let alone claiming Jesus will appear on stage.
Problem is, many Christians follow people like HInn and Bentley and will not hear a bad word against them, the more they lap up thier teachings and lies, the more they put thier salvation in jepordy, the more they walk away from God. following these people is not good for spiritual health and even physical if you have the mis-fortune to be "healed" by Bentley.
We should not call people who have minor disagreesments over theology, "false teachers" or "wolf in sheep clothing", no all the time we pick holes in theological difference, the real wolves and real false teachers are at work being un noticed.