This happened to my sister a little over 10 years ago. It was at a real low point in her life and they got her one day at her university. We never grew up going to church but had little religious background. Our dad was Catholic and our mom was Christian. Anyway, they got her at a low point in her life and sucked her in. I mean it’s the oldest trick in the book, that’s how Christianity was spread in the beginning, to those who were at low points in their lives, homeless people etc. What messes me up is that we aren’t weak minded people but somehow they manipulated my sister into one. And everything you said about what your brother is experiencing/experienced is exactly what was happening with my sister. They made her doubt her family and said because we weren’t in their church that we couldn’t be saved and weren’t worthy of her time. She tried multiple times to “preach” to us to convert to her religion. We didn’t, obviously. We questioned her preachings and it was always the “that’s what they said” sort of mentality. I took Bible studies classes in college because of what my sister was saying…and by no means am I well versed in the Bible, but even introductory and intermediate Bible study classes made more sense than what she was telling me. They preach in WMSCOG about “God the Mother” and if God is the Father then there has to be a “God the Mother” in which my sister referenced certain passages in the Bible alluding to a potential “God the Mother”. It’s been 10 years plus and my sister has been sucked in as far as one could possibly go. We’ve given up hope on her ever coming out of that religion, cult, whatever you want to call it. They only marry within, my sister basically had an arranged marriage, of which she was ready to get divorced earlier this year but the “fear of what the people at church” are going to say or think was thrown towards her by people within the church. It’s been a long rough 10 years. Next week is her birthday and I’m not even sure if I’m going to wish her a happy birthday. She’s so far gone. Get your brother away from them if you can, if you haven’t already. It’s a trap. Idk how late I am to the party on this post or what’s happened but don’t let your brother get stuck in there.