To make you know the certainty of the words of truth, that you may give a true answer to those who sent you? [Luke 1:3, 4.]
That I might make thee know the certainty of the words of truth; That thou mightest answer the words of truth to them that send unto thee?
To make thee know the certainty of the words of truth, That thou mayest carry back words of truth to them that send thee?
Their purpose is to teach you true, reliable words, so you can report back reliably to those who sent you.
so that I might reveal to you, firmly and with words of truth, in order to respond about these things to those who sent you.