Luke 1:4 in the World English Bible
that you might know the certainty concerning the things in which you were instructed.
Context
3 It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus,
4 That thou mightest know the certainty of those things, wherein thou hast been instructed.
5 There was in the days of Herod, the king of Judæa, a certain priest named Zacharias, of the course of Abia: and his wife was of the daughters of Aaron, and her name was Elisabeth.