"Young men are to use sound speech, that cannot be condemned; that he that is of the contrary part may be ashamed, having no evil thing to say of you" (Titus 2:7-9).
Is this scripture guarantee that behaving in a certain way protects a person from other speaking evil against them? No. It does mean that the person who us of sound speech will continue to have a clear conscience.
A clear conscience is a much lighter load than pretending to have one.