The word 'measured' would be appropriate, and particularly appropriate for the chosen example sentence.
b. Of aspects of language: carefully weighed or calculated; regulated, moderated, restrained. Of a person: using language in a careful, restrained way.
We should be measuring our words carefully because we will have to give an account for them someday.
Bible Verses About The Power of Words
'Measured' implies thoughtful preparation and also implies care about content as stated in Ecclesiastes :
Be not rash with thy mouth, and let not thine heart be hasty to utter any thing before God: for God is in heaven, and thou upon earth: therefore let thy words be few.
