It's true that many people are "indoctrinated" and end up on islands. There are also people who are on islands of being "open to everything" but never having set standards of right and wrong. These islands do not depend on the issues in hand, it is just your approach to truth. You can either consider truth to be whatever can be scientifically proven, or you base your idea of truth on what you have seen and experienced, or you can start with a worldview and build walls of truth around it.
I think the most important thing for everybody to know is what they beleive, and why they beleive it. If you don't know what you beleive, you are just another creature following its instincts; if you don't know why you beleive what you beleive, you might as well just be another creature following its instincts.
I don't know about everybody else here, but the meaning of life is very important to me. If I am here only because some mud mutated, and if after I die, I just turn back into mud, there is no reason to do anything different from the animals, no reason not just to follow my instincts. Yet I am convinced that there is a purpose for everything, and that with the existence of time and space, there is automatically an existence for reason. After all, you could say that we are just a natural miracle that happens on a little ball spinning around a little star which makes up part of a little galaxy suspended in space. However, the very fact that we can reason, that we do reason, and that we need truth, leads me to beleive that there reason and truth must exist in this universe.
Now, if reason exists, then there must be a reason for the existence of the whole universe, let alone each little part that works perfectly together. Is the whole universe just the result of random chance? Then how did it all begin? If it is all random chance, then why is the blue sky attractive to us, and why do we like to look and smell flowers, even if we don't even pollinate them? And why are we not content with the world we have built ouselves? Think about it - why are the rich, who can have anything they want, still not happy?
Perhaps someone wanted to make us like him; creatures he could know personally. In this case he would have made us in a way that we don't automatically worship him. He would give us choice, and see what we do with it. It would make sense, in that case, that he'd have standards for us, to determine which ones he keeps, and which ones go into the fireplace. Maybe we were designed so that we are only happy if we know the guy who created us. Maybe that's the reason I do what I do, why I go to the trouble of being a "Christian"...
Peter