I never thought of it as overtly religious. I think with eustace saying “I could not do it myself” he accoplish the same end. (only through me ...)
“it hurt but a good hurt like a thorn being pulling. or words to that effect)
Between that line, and Ramandu's daughter saying of Aslan's table "It is FOR YOU" (with strong emphasis on the last two words) all of sacramentology that I had loved in the book was displayed...perhaps even better than in print, for it is difficult to show inflections and emphasis in the written word.
The filmaker turned the Anglican Lewis into a fine Lutheran, IMHO.