I'm not sure that fundamentalism is a mental illness. The person having those extreme views may have mental illness,who knows? But, people need something to hold onto. They,in general, need to believe in something, to have faith so they feel they belong to something greater than themselves, so that they are not alone. Unfortunately,some people take those beliefs to an aggressively extreme length and try to force their beliefs on others. They tend to have a superiority complex, thinking their beliefs make them better than those who do not share their thoughts and ideas. Now, how do you deal with someone who is in your face telling you that you are not saved? Smack him in the face...HARD. Just kidding! I think you could tell him that you understand that he has strong feelings about his faith, but you also have strong feelings about your faith. Tell him that if he chooses to be overly aggressive to the point of harrassment, then perhaps you two have nothing more to say to eachother. That's it. Over. I realize it is family and you will see him occasionally. But, you do not have to socialize. Keep your distance. Avoid eye contact. Just know in your heart that you accept him for who he is, whether or not you support his views. If he cannot accept who you are despite his difference in views, you have nothing more to say. Conversation will only cause you both upset. Just let it be.
Well, that's my advice,Ayshah. I hope it helps a little. Or maybe gives you a different point of view.
~Love and Light To You and Yours~
~Lisa

I grew up in a fundamentalist environment, which only became more extreme during my late adolescence and early adulthood. It never sat very well with me. I broke away from it in stages -- first by becoming a conservative evangelical Presbyterian, and later by becoming an Episcopalian. In the Episcopal Church, as an extension of the Anglican tradition, I perceive that Christ's work is being done. Jesus was not a purveyor of social boundaries and hate. He always drew the larger circle and took within it the outcasts, the poor, the diseased, the marginalized -- even (gasp!) women. That's what the Episcopal Church is all about -- for the most part.

What can you say to fundamentalists? Maybe gently remind them of what they could learn if they carefully read the Bible -- that Jesus was a party animal with sinners, that he invited the sinless to cast the first stone, that he told us to care for the poor and the prisoner, that he told us to give it all away (not take Visa cards over televangelistic telethons), and that the fundamentalists of his day were the ones he decried -- the Pharisees.

Hang in there. With all its problems (and its burgeoning schism over a gay bishop and a female presiding bishop), the Episcopal Church honestly tries to grapple with the truth of Christ's message and live it in the real world.