KJV:
Bless them that curse you, and pray for them which despitefully use you.
NASB:
bless those who curse you, pray for those who mistreat you.
KJV:
Having a good conscience; that, whereas they speak evil of you, as of evildoers, they may be ashamed that falsely accuse your good conversation in Christ.
NASB:
and keep a good conscience so that in the thing in which you are slandered, those who revile your good behavior in Christ will be put to shame.