Are Chaplains "Christians"?!

Are Chaplains in the Armed Forces, Prisons, Hospitals and Police, really bible believing Christians, or are they expected to be ecumenical in their approach?
“And he said unto them, Go ye into all the world, and preach the gospel to every creature.” (Mark 16:15)
https://www.azquotes.com/quote/1073373?ref=chaplains
https://www.vonnegut.com/
https://www.vaticannews.va/en/vatican-city/news/2022-10/vatican-ii-council-60th-anniversary-video-history-background.html
https://webstersdictionary1828.com/Dictionary/religion
https://thechaplainkit.com/history/chaplain-school/foreign-schools/armed-forces-chaplaincy-centre-u-k/
https://prisonfellowship.org.uk/our-work/chaplaincy-support/
https://www.healthcareers.nhs.uk/explore-roles/wider-healthcare-team/roles-wider-healthcare-team/corporate-services/chaplain
https://www.policechaplaincy.uk/faith-information/faith-information
https://www.e-sword.net/
https://www.purebiblesearch.com/
https://www.jw.org/en/library/bible/study-bible/books/
https://www.azquotes.com/quote/856730
@ScourbyYouBible
https://www.youtube.com/@ScourbyYouBible