Here is the Mural that we see in the bunker for you to ponder.

4+8+15+16+23+42=108, Sick, Rocket, People, Homes, Water, Sun, Pa Qua Points, Dharma, dark, light, faith, fate, natural, supernatural ... etc.

My guess right now for the show is that the island could be host to an abandoned weapon ...a chemical weapon, or nuke maybe... end of the world type weapon...something very destructive… that is only kept from going off by the people brought to it...the force that guides people to the island to stop or keep the weapon from going off could be supernatural which would account for the coincidences we see in how things have come together. Each person is there for a reason for a purpose…. The 4-8-15-16-23-42 seats on the plane all seem to have some part to play even if small and right now I think the goal is to keep mass destruction at bay….at least something very dangerous from happening.