Wait a minute, I think you are mixing something up. It does say that we should not say the name of Jesus Christ, but it does say specifically, which you either forgot or ignored, that we should not say the name of Jesus Christ in anger or as a curse
So when a Church clergy says " in the name of Jesus Christ Amen" at the end of a prayer or speech is perfectly okay
I was talking about the disciples who were brought in front of the courts and told to stop using the name Jesus Christ.