By the passing of years it happened that some pupils came to take over teachings from other cultures and religions and as such became considered to be antichrists.
In Christendom there are groups who find themselves exclusive, believing they are the holders of the absolute truth, while all others are heretics or even the work of the devil himself.
Often a lot of people do not know to differentiate between Christendom, Christianity, religiosity and even limit religiousness to Christians, forgetting that there are many other religious groups who have all sorts of worship.
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.