I use to help with youth camp years ago. I have been long aware at mischief coming through church people. I told a brother one day that I was worried about the operations of the devil through church people. Ohh... He says... The devil cannot go against the blood... And his contention was so great that he reported me over it.
Years later, at camp meeting, that brother came to me and personally apologized. I graciously accepted, but deep down, wondered what trials the poor man went through to come to the same conclusion, that yes, the devil can operate through church people and that it is a sad truth.
I was very naive, not having been raised Christian - I automatically trusted those who held the label. And I was hurt - very badly. So your experiences definitively jive with mine.