to make Christian or convert to Christianity to imbue with Christian principles, spirit, or outlook 
WordReference Random House Unabridged Dictionary of American English © 2025
Chris•tian•ize 
(kris′chə nīz′),USA pronunciation v.t., -ized, -iz•ing. 
 Chris′tian•i•za′tion, n. 
Chris′tian•iz′er, n.
- Religionto make Christian.
 - Religionto imbue with Christian principles.
 
- Christian + -ize 1585–95
 
Chris′tian•iz′er, n.
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'Christianize' also found in these entries (note: many are not synonyms or translations):