The sheep in the field (Chisholm 1966/1977/1989). Imagine that you are standing outside a field. You see, within it, what looks exactly like a sheep. What belief instantly occurs to you? Among the many that could have done so, it happens to be the belief that there is a sheep in the field. And in fact you are right, because there is a sheep behind the hill in the middle of the field. You cannot see that sheep, though, and you have no direct evidence of its existence. Moreover, what you are seeing is a dog, disguised as a sheep. Hence, you have a well justified true belief that there is a sheep in the field. But is that belief knowledge?
First self-applied as a term to the conservative doctrine outlined by anti-modernist Protestants in the United States of America,  fundamentalism as a religious belief is associated with a strict adherence to an interpretation of scriptures that are generally associated with theologically conservative positions or traditional understandings of the text and are distrustful of innovative readings, new revelation, or alternate interpretations. Religious fundamentalism has been identified in the media as being associated with fanatical or zealous political movements around the world that have used a strict adherence to a particular religious doctrine as a means to establish political identity and enforce societal norms.
As you can see, justification leads to an infinite regress. There is no end to the justifications needed. There are two ways to try to get out of this problem. The first is circular. You use J 2 to justify J 4 , say. But circular arguments are invalid. The second way out is to declare some ideas to be self-evident or self-justifying. When you get to them, you just stop, and you never consider if they might be mistaken. This is circular too. It's justifying J 4 using J 4 . Further, how do you decide which propositions are self-justifying? You'll need an idea about that, and it needs to be correct, so you better justify it. No problem has been solved.