It is striking that there are a lot of people in the world who are opposed to those who worship Jehovah as their only true God. The vast majority of those anti-Jehovah people come from extreme right-wing groups and fundamentalist or very conservative Christian groups.
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.