God botherer

Wiktionary

1. n. UK, slang, pejorative A person who persistently promotes religious beliefs to others, even when unwelcome.
2. n. Australia, New Zealand, slang, pejorative A religious preacher who visits homes to promote his or her beliefs.
3. n. UK, slang, pejorative An excessively pious person.
4. n. UK, military slang A military chaplain.