missionary / preacher / priest

missionary   傳教士
a person who is sent to a foreign country to teach people about Christianity

preacher   
a person, often a member of the clergy, who gives religious talks and often performs religious ceremonies, for example in a church

priest 
a person who is qualified to perform religious duties and ceremonies in the Roman Catholic, Anglican and Orthodox Churches





https://tw.dictionary.yahoo.com/dictionary?p=missionary
https://www.oxfordlearnersdictionaries.com/us/definition/english/missionary?q=missionary

https://tw.dictionary.yahoo.com/dictionary?p=preacher
https://www.oxfordlearnersdictionaries.com/us/definition/english/preacher?

https://tw.dictionary.yahoo.com/dictionary?p=priest
https://www.oxfordlearnersdictionaries.com/us/definition/english/priest?q=priest