First of all, I can see why early Christians, especially Greco-Roman Christians, get so excited about this setup of Plato's. Four hundred years after him, this guy with a beard comes out of Nazareth and says, "I am the light of the world." As reward for confronting and ending oppression, he gets the crap beat out of him, to boot. Just that would put the Cave on the Christian's reading list. But the whole underlying motif is very congruous with much of the Judeo-Christian tradition, in that humanity's fallen nature does impede our full vision of reality, such that only the divine light reveals what is true about reality. Even the idea of 'forms', which admittedly doesn't find alot of traction in a Jewish worldview, can be understood as the 'thoughts' of God the Creator - his final, eternal and perfect vision of how reality ought to be, only dimly and somewhat progressively revealed to chained and fixated minds.
So I guess you can say, if you want to understand what Christianity has done with thinking through the Christ-event, Plato's cave seems to be a necessary step, since virtually every Christian thinker has been exposed to the idea in some way. And now I have. Huzzah for me.
But this whole fable of Plato is such a burr in my stockings because it's not as simple as that. And so many have figured this through that my munchings are just tiny nibbles, but they take all my brain.