When the Apostle John spoke of those who do not "abide in the teachings of Christ"?

Dude I can only tell you what I think.Those that don't abide in the teachings of Christ wold be Jehovah's Witnesses, Mormons(Latter-Day Saints), Catholics, Jews, and other as such. I tell you this because in these religions you will find things that ARE TOO DIFFERENT from the Bible. Heck, they even have their own 'holy' book. Think about it. The JW's reject Christ and call Him 'a god', Mormons say Christ was Satan's brother and that one day they'll fly to a planet and mate and have many children, Catholics worship Mary and other saints, either by bowing down or kissing them and they make it seem like God and Mary share power, and Jews reject Christ even today and are waiting for Him to come in physical form as was said but it already happened. Oh, and I forget Islam. You should know that Islam says that Christ wasn't who He said He was. I hoped this helped. Have a good day.