Jacques Ellul, the person throwaway7 cited as quoting Maria Motessori. Ellul was a Christian anarchist, which is of course redundant for most modalities of “Christian.” It explains the context of the Montessori reference, to me at least.

Edit: a nice concise explanation of his view on pedagogy and montessori: https://m.youtube.com/watch?v=jVvpVXdhCQg