Where does “基督教” come from?

基督教 (Chinese) comes from Japanese 基督教, from Japanese 教, from Middle Chinese 教.

Ancestry of “基督教”, step by step

Step	Language	Word	Meaning
1	Japanese	基督教	—
2	Japanese	教	-ism
3	Middle Chinese	教	—

基督教 — Etymology, Origin & Word History | Etymology Explorer