We send is literally “we have sent,” a verb tense which reflects the point of view of the readers of the letter and not of the writer. Who will tell you in person the same things we are writing is literally “and they through a word will tell the same things.” “Through a word” means “by word of mouth,” which the Good News Translation takes as equivalent to in person. And “the same things” is a specific reference to what was written (see Jerusalem Bible “what we have written in this letter”). The meaning of this entire verse is that the written message from the Council and the oral message by the messengers would be identical. This last clause may be rendered in some languages as “they themselves will tell you the same thing as we have written” or “their words, which they will tell you themselves, will be the same as the words which we have written.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .