Cross reference
Proverbs 22:21
21 To make thee know the certainty of the words of truth, That thou mayest carry back words of truth to them that send thee?
Luke 1:3-4
3 it seemed good to me also, having traced the course of all things accurately from the first, to write unto thee in order, most excellent Theophilus;
4 that thou mightest know the certainty concerning the things wherein thou wast instructed.
1 Peter 3:15
15 but sanctify in your hearts Christ as Lord: `being' ready always to give answer to every man that asketh you a reason concerning the hope that is in you, yet with meekness and fear:
John 20:31
31 but these are written, that ye may believe that Jesus is the Christ, the Son of God; and that believing ye may have life in his name.
1 John 5:13
13 These things have I written unto you, that ye may know that ye have eternal life, `even' unto you that believe on the name of the Son of God.