Based on my experience with literalist believers, it seems to me you're faced with a binary choice - to confront their beliefs (as diplomatically as possible, of course) or to remain silent. No matter how diplomatic and empathetic you try to be, if you question their beliefs in the slightest, they are going to take offense.
The attitude you describe sounds very much like that of Jehovah's Witnesses, who do not celebrate Christmas or Easter and seem to want to put the bible and Jesus in front of everything and everyone. As I understand them, they are also not very much about higher education, excepting trades and the like.
My attitude toward them would be this: We live in the 21st century, a time where science and technology provide benefit for those who use them whether they believe it them or know how they work or not. Science and technology depend far less on belief than they do on KNOWLEDGE, and not at all on unsubstantiated faith. If they are willing to have a conversation based in what we KNOW and can verify to be factual, then fine. If every challenge to their belief is responded to with, "Well, the bible says...", then there is no basis for discussion. The bible is flawed way past any chance that it can be taken seriously in any historical context. So long as it is their focus and they cannot be as critical of it as they might be any other referent, I simply would not waste my time.
" I will have to accept the authority of Scripture, the harmonization of the gospels, the abundance of independent extra-biblical (yet anecdotal) evidence for the existence of Jesus, and more."
Josh, what a terrible dilemma you face. If you break it into small chunks it may be easier to come to a decision that you can live with.
I assume this is your brother and his wife and family are fundamentalists.
How do you feel when you are with your brother, alone. Can you speak freely with him? Can you ask him the tough questions that you pose here?
It seems to me you have the right and responsibility to ask the tough questions of your family member. You would ask a sibling the tough one if he or she were abusing alcohol or drugs. Religion is a far more difficult topic to confront. I believe it has to be done.
How do feel when you are with his family? Do you want to ask the tough and remain silent?
Do you want to maintain the relationship if their religious beliefs get in the way of good relations?
Do you bring up the subject of religion?
In my experience is not a good idea to bring up the subject until and unless you see harm to your extended family members. Religious call abuse discipline ... I know from experience and my children paid a heavy price for my not responding sooner. The good news, I raised them as a single mom and they turned out to be fine citizens. I think it can be done as a single dad too, but parenting is always a crap shoot.
What do you do if someone else brings up the subject of religion?
I always respond, unless there is some compounding variable i.e. when death is involved. My approach is to respond back mirroring the temper and one of the other. If someone speaks lightly, I answer back with a matter-of-fact response. If the other is aggressive, I stay calm, firm, competent, confident, and ask the hard questions. I had to do a little homework to be prepared for this event. But it isn't hard, just watch a few debates, especially by Hitchens. His arrogance puts believers off, but the content of his responses are gems.
Can you have a family gathering without the fundamentalist ones attending and have fun?
My experience is that I have fun whether the fundamentalists attend or not. If I am not having fun, I can always leave, unless, of course, I am hosting. If I am hosting, and if the fundamentalists become uncivil, I ask them into my office and describe how their behavior is unacceptable and invite them to leave if they cannot be civil.
"I will have to accept the authority of Scripture, the harmonization of the gospels, the abundance of independent extra-biblical (yet anecdotal) evidence for the existence of Jesus, and more."
"NO! YOU DO NOT HAVE TO ACCEPT"
You do not have to accept any uncivil, disrespectful, aggressive behaviors. If your brother is an attorney, he will understand building a case for one side or the other. You can build a case very quickly and easily to refute the bible if that is the direction you wish to go. I far prefer the
I have a playlist that is well over a year old and there probably are more up-to-date videos available.
You can be pretty smart and still batshit insane to. When people believe so strongly like this, you just gotta walk away man. It's quite literally delusional, after awhile it feels as though you're visiting a mental hospital. "Sure man, the government totally put a tracking device in your brain" walks away slowly.
Perfect! You have the idea. Now, over time, and with skill, perhaps your family can be reconciled and have joy in being together. Good job.
This is very hard to do. You have to keep a calm voice, ask questions, and ask them to explain their beliefs once you get down to basics. The bottom line on their part will always be like "I just know it by faith, god told me so, or the Bible says." In a world of all the possible religions they see theirs as the only true and right one. It never occurs to them that religion has a lot to do with the area of the world you are born in and that goes right back into the religion your parents had.
As for your friend's aversion to Christmas trees he might quote you Jeremiah 10: 1-10 if he is an extreme fundamentalist in his beliefs. Even so, Christians cannot "own" Christmas. They keep wanting to stick Jesus in there because "he is the reason for the season." Since when and says who? I can tell them where to stick Jesus.
When it comes to this man wanting to teach his children that Santa is a lie and Jesus is true, it will turn on him in latter years as the kids mature. A thinking child will not understand how all of our information is on the Internet today, but the only thing you can believe there is what your church says is true. Being home schooled used to be a way to avoid it. Today the Internet is where god comes to die.
This will happen because there is no "harmony of the gospels" and no evidence of god. All the holes and contradictions of the Bible are laid bare today, but they were easily hidden without the Internet.
Sorry I'm not responding with what you want, but I find some of the things you say trigger a response in me. At age 73, I don't have the patience or the time to pussy-foot around with the religiously brainwashed, such as my family.
I finally broke-out of my indoctrination, and If they can't see the evidence I give them, too bad. I suffered fear and guilt many years because of religion, and I "deserve a break today". I'm not willing to suffer any more aggravation talking to them.
In the few years I have left, I want to spend it with reasonable people.