As Christians we have to be very careful about who we listen to.  More importantly, we need to be in the Word daily for ourselves so that when we come across people who try to tell us things that are contrary to God's Word we will recognize it!  In Acts 17:11 it says that the Bereans were more noble than the Thessalonicans because they went and searched for themselves in the scriptures to make sure that this new information Paul was presenting to them actually lined up with God's revelation.  This was noble in God's eyes!  We can't get caught up in the idea that if a person claims to be a preacher that what they are saying is truth.  Any person who gets upset or annoyed -- or downright angry -- at the idea of someone looking into scripture to double check them is not a person you should follow or listen to.  God's leaders are to be humble.  They welcome the accountability of people who rightly divide the word of truth and bring to their attention where his ideas and God's revelation doesn't meet up.  A leader should be approachable and not take offense at any questions you might have.  Do they display the character of Christ??  Sadly, true Christians can be leaders who are puffed up and get carried away with "power."  Not all teachers of error are minions of the devil.  Some are truly mistaken.  But if you try to approach them about the discrepancies you see in what they teach, how they live, and scripture, and they react in anger or dismiss you without giving it honest consideration in prayer, then shake the dust off your feet and move on.  Don't get sucked into error!