8 and soundness of speech that cannot be condemned, so that those who oppose you may be ashamed because they have nothing bad to say about us.

Read Titus 2:8 Using Other Translations

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.
and sound speech that cannot be condemned, so that an opponent may be put to shame, having nothing evil to say about us.
Teach the truth so that your teaching can’t be criticized. Then those who oppose us will be ashamed and have nothing bad to say about us.