The fundamentalist community has strong walls and high gates to protect itself against the world around it. In order that fundies may soil themselves as little as possible with the evil that lurks outside the sacred bubble, they attempt as much as possible to replicate every facet of secular life in fundamentalist hues inside this shell.
In short, the fundamentalist organization will attempt to become everything to you who are held in its dread sway. They are your church, your employer, your schools, your social sphere, your sports team, your library, your music publisher, your landlord, and oh, so much more.
This creates the happy circumstance where, to many people, leaving fundyland means not only losing your church but also your children’s education, all your family friends, your job, and maybe even your house. Many are those who grunt and sweat under a weary life in fundamentalism because they have no idea where they would go or how they would live if they left.
How do you get a job in the outside world if you know nobody there and your qualifications only exist inside the fundamental sphere? Would you risk consigning your children to the deviltry of public schooling if leaving your church meant that they could no longer attend the one they are in now? How do you make friends of the evil people in the cold, cruel world?
Hopefully one day you’ll find out that the pay is better, the people are nicer, and life is so much sweeter outside those walls. The only difference between a castle and a prison is whether you’re trying to keep the people out or in.