In all manner of conversation,we must be Practicing Holy Discourse (P.H.D) for our conversation (citizenship) is not of this world but of heaven (Philippians 3:20). Our manner of conversation must be of holy and heavenly matters.

1 Peter 14-16 (KJV)
14 As obedient children, not fashioning yourselves according to the former lusts in your ignorance:
15 But as he which hath called you is holy, so be ye holy in all manner of conversation [discourse];
16 Because it is written, Be [practice] ye holy; for I am holy.