She was one of my deep early influences, ever since the day lucy_anne handed me a copy of A Swiftly Tilting Planet when we were both teens.
As a teen I identified deeply with Meg Murray, and felt like Meg was a friend, a companion through adolescence.
As an adult, I look back and see in L’Engle’s work some of the threads of my own adult worldview: the belief that there really is a lot of good and light and most of all fundamental all-rightness in the world; the belief that there may be a lot of darkness too, but it’s the all-rightness that wins in the end. The sense that the end of the world is never inevitable. The knowledge that it’s okay to have rough edges, that they make us human, that sometimes they even save that world.
No doubt there are other sources for these beliefs too. But Madeleine L’Engle was one of them.
But even if she hadn’t been, her books were a comforting presence throughout my adolescence, and that alone would be enough.
ETA: curtana‘s L’Engle tribute.