I NEED YOUR OPINION ABOUT NEW "PROPHETS"

Do you believe that we are given new prophecies that are not already foretold in the Scriptures?  I'm referring to the prophets of the churches like Jehovah's Witnesses (Russell Tase?); Ellen G. White of the Seventh Day Adventists; and Joseph Smith of the Mormons that do not line up with scripture?  What I believe is some are able to have a much clearer understanding of prophecy but I do not believe in new prophets that go outside of scripture or do not line up with what the Canon says.  We are warned not to add or take away from the Bible.  Of all the above new churches and prophets, none of their prophecies came to pass, they all have outside publications and/or Bibles that are rewritten to fit their doctrines and when read, they are far from other Bibles.  Does God not tell us that if someone says something in His Name and it doesn't come to pass, to dismiss them as false prophets?  In the OT, these "prophets" were stoned to death!  God considers this an extremely important issue.  Jesus Christ did NOT come back secretly in 1914 or 1917, depending on who you listen to.  The Watchtower is full of occult symbols and denies Jesus Christ is God and say He was created.  They deny the Godhead.  SDAs put us under the bondage of the law and claim Jesus is really the archangel Michael (as does the JWs) but say He isn't created.  They all say they are THE only ones going to Heaven.  Mormons believe Jesus and satan are brothers but doesn't John 3:16 say that God has only ONE BEGOTTEN SON?  Please be careful.  I watch a lot of videos (well, I see them) that claim extra-Biblical revelations by so many.  I hear people claim that God gives them messages that don't line up with scripture.    Now my husband did have an out of body experience during surgery and what he saw, I do believe he did but he didn't go to Heaven.  Read Paul's very humbling account of when he went to the 3rd Heaven.  He was so humbled by it, he said it in the 3rd person and said he was forbidden to tell man.  I'm not sure what to believe on NDEs.  Some line up with scripture.  What is your thoughts?  I'll be clear, I do not believe we are given new revelations from God.  I also do not believe in new doctrines.  If you want to know what He says, read the Bible and listen to those who have a good understanding of prophecy.  Be wary of those who claim extra-Biblical info.  You must test all spirits to see if they are of God because even satan can appear as an angel of light.  LEARN TO DISCERN. God bless.