You have every right to be upset and your criticisms are perfectly valid. Just remember it’s not worth endangering yourself to debate a brick wall. I’m sure you have plenty of well thought out points, questions, and criticisms, the only thing is that I fear it doesn’t matter. It is probably close to impossible to change their views on religion no matter what is said (implying I have interpreted the situation you face correctly), and if what you said is true it sounds like you could face serious repercussions from your family for speaking out. I don’t see any scenario in which this ends up benefiting you, it sounds to me like you’re going to debate a brick wall just for it to remain a brick wall and for you to become homeless.
Your frustration and anger are valid do not get me wrong, but some things are not worth it. I commend you for wanting to stand up against injustice but at the moment you are a lone rebel against a entire militia, fall back, regroup, live to fight another day.
If you do go through with it do not escalate, in terms of wether or not the religion is correct just remember no one truly knows if there is a god or where we came from. It is very difficult to argue a counter point when the counter point doesn’t exist. I am always very careful to acknowledge the persons religion very well might be true, I don’t know, I simply have questions and criticisms. I simply try to point out the specific spots that trouble me with the religion and I give them the opportunity to remedy my discomfort, I don’t tell them “it’s wrong because of this” I try to say “ok, but these two things seem like a logical contradiction to me, what do you think?”. In my experience the only real way to bring change in their thinking is to ask questions and have them figure out the flaws on their own as they attempt to answer my questions. Direct confrontation doesn’t work.