Perhaps a good subject for personal study night would be who the mediator for all of mankind is, according to the bible (not their literature). There are so many scriptures that state that there is only one mediator between god and man, that no one comes to the father except through ME (not a group of men), that there is one faith, one hope. Discuss whether Jesus ever directed his followers to look for a group of men to interpret the bible and direct them, whereas he said that where two or more are gathered in my name, there I am among you. And by the way, where did he say he is coming invisibly? He said the exact opposite, that if someone tells you I'm in the woods, or where ever (invisible), don't follow them. The parable of the FDS is just that, a parable. Hmmm, wonder why they chose that parable to apply prophetically to themselves? Might it be that it conveniently confers power to them over "all of the household"?
I dunno, just a few things that got me thinking and doubting. You can prove these point using only the bible, whereas she can't defend them using the bible.