Mother takes Jacob & MIB to the cave of light, the manifestation of life, death & rebirth

As Mother tends to her garden, Jacob and the Man In Black run back to tell her about the men they saw who killed a boar. Jacob asked her where they came from and says they look like them. She says that they're not like them and they don't belong there because she and boys are there for a reason. MIB asks her what the reason is that they are there, and she says it's not time, but he repeats his question more emphatically.

Not long later, we see Mother leading the boys who are blindfolded through the jungle. MIB asks her if she knew about the people, and she says yes. He asks why she didn't tell them about the people and she says because they are dangerous and she didn't want to frighten the boys. When Jacob asks what makes them dangerous she says "the same thing that makes all men dangerous" Then we hear her repeat MIB's line from "The Incident," which is "They come, they fight, they destroy, they corrupt... and it always ends the same."

When MIB then asks where the people came from, she lies and says from another part of the island. She says that they can never go looking for them because if they found them, the people would hurt them. We Jacob asks why the would hurt them, Mother says that it's because they are human and that's what they do.

MIB says that they are people too, and asks if that means they can hurt each other. Mother removes their blindfolds and tells them that she has made it so they can never hurt each other.

Mother turns the boys around where they can see a stream of water flowing into a tunnel with a bright, glowing, yellow light. She tells them that this is the reason they are here. As the boys approach the tunnel, she tells them not to go in.

She says that the light inside is the warmest, brightest light they've ever seen or felt and they must make sure that no one ever finds it. She says that there is a little bit of this light inside of every man, but they always want more. She says that no one could take it, but if someone tried to, they could put it out. She adds if the light goes out there, that it goes out everywhere. She says that she has protected this place, but she can't do it forever, and one day, either Jacob or MIB will have to do it.

Whew. That was a heavy scene. So we a general idea of what is being protected on the island and that it can be accessed from this secret location. This poses a lot of questions that there is not time to answer, but has any unauthorized person every accessed this location during their time on the island? What will happen if this light goes out? Something tells me that this location may have something to do with why Desmond was brought back to the island.