Cross reference
Proverbs 22:21
21 To cause thee to know the certainty of sayings of truth, To return sayings of truth to those sending thee.
Luke 1:3-4
3 it seemed good also to me, having followed from the first after all things exactly, to write to thee in order, most noble Theophilus,
4 that thou mayest know the certainty of the things wherein thou wast instructed.
1 Peter 3:15
15 and the Lord God sanctify in your hearts. And `be' ready always for defence to every one who is asking of you an account concerning the hope that `is' in you, with meekness and fear;
John 20:31
31 and these have been 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 I did write to you who are believing in the name of the Son of God, that ye may know that life ye have age-during, and that ye may believe in the name of the Son of God.