Reverence the holy names God and Jesus Christ. Blasphemy and cursing. Profanity is a venial sin if a person does not try to break a habit of misusing a holy name. Vulgar language is not a sin, but it may be socially unacceptable. A gentleman or lady does not offend by crude speech.
Courtesy characterizes Christian conversation.
The original Christians. A saintly Catholic worker used to doff his hat whenever he heard the name Jesus profaned. Many Catholics bow their head slightly at hearing the name Jesus. Substituting phonetically similar but otherwise inoffensive words. Because it can mean A. take an oath, or B. misuse a holy name.