noun
Refers to a person who follows Christianity. Neutral term.
彼は敬虔なキリスト教徒です。
He is a devout Christian.
Also means 'Christian', but is a loanword from English and can sound more casual or modern. キリスト教徒 is the more formal, descriptive Japanese term.
Compound of キリスト (Christ) + 教徒 (follower of a religion). キリスト is from Portuguese 'Cristo'.