I
Luke 1:3
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,
Luke 1:4
That thou mightest know the certainty of those things, wherein thou hast been instructed.
John 20:31
But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
1 John 5:13
These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
answer
1 Peter 3:15
But sanctify the Lord God in your hearts: and be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear: