BROKEN STEEL BELTS
It is impossible to be prepared for every error around. When I bought my dad's old car, it had been sitting idle for a year. He had hardly used it; even the tires were original -- nine years old. When I brought it in for a flat tire, the mechanic fixed it and all seemed well. The next day, it was flat. I took it back. When I went to retrieve it, the mechanic said it had to be replaced. The steel belt had broken. Whenever he patched one hole, another would appear.
That's how false teaching is. It is relentless. Thus, the only way to be prepared is to be able to recognize true teaching.