Doctrine Saves?

Someone wrote:

Some people really think that Jesus said, By their doctrine you shall know them. That always baffles me.

Look these passages up:

Take heed unto thyself, and unto the doctrine; continue in them: for in doing this thou shalt both save thyself, and them that hear thee.

Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son.

Turns out doctrine really does matter...

So, why stay away from Chuck Smith and his disciples?

Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them.