People should know that false teachers will teach anything they believe, and not from the Bible. People also should look at the preachers their behaviour and see if they have the Holy Spirit in them, following, living according and teaching the words of the Holy Bible. Often their way of talking, using a language which is not according the way Jesus would talk shall dismantle them and should be a sign for you that they are not the right one to follow.
KJV-only people often forget that in the many Bible Translation committees, all over the world, can be found many serious honest people who like to do justice to the Word of God. Several brainstormers from all sorts of religious groups often work together as a team to sit down to do some good bible hermeneutics for getting the best contemporary words placed in good readable and understandable phrases.