Phrase this as you will, but I'll say this...

Jane Eyre is primarily thought of as a romance, but I disagree with that idea. I think it's primary theme is about religion. Christianity permeates the book. Jane starts out almost as a pagan character who through the exposure to Helen Burns and Miss Temple (and with Brocklehurst as a counter-example) Jane develops a deep sense of Christian right and wrong which she carries with her through the rest of the story.

Edward's redemption comes through pain & suffering and his acceptance of the sinner he is. With his acceptance of God, he gets a Godly marriage with Jane, a son and partial restoration of his eyesight.

The story is bookended with two Christian martyrs: Helen and St. John. Just look at what the book closes with.

Yet, when you look at the adaptations, even the closest of them (the one with Zelah Clarke and Timothy Dalton) strips out most of the religious theme.