Luke 1:3-4

it seemed good to me also, having carefully investigated all things from the very first, to write to you an orderly account, most excellent Theophilus,

1 Peter 3:15

but in your hearts reverence Christ as Lord. Always be prepared to make a defense to everyone who asks you to give an account for the hope that is in you, yet do it with gentleness and respect;

John 20:31

but these are written that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in his name.

1 John 5:13

I write these things to you who believe in the name of the Son of God, so that you may know that you have eternal life.

Treasury of Scripture Knowledge

Summary

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?

Answer

Bible References

I

Luke 1:3
it seemed good to me also, having carefully investigated all things from the very first, to write to you an orderly account, most excellent Theophilus,
John 20:31
but these are written that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in his name.
1 John 5:13
I write these things to you who believe in the name of the Son of God, so that you may know that you have eternal life.

Answer

1 Peter 3:15
but in your hearts reverence Christ as Lord. Always be prepared to make a defense to everyone who asks you to give an account for the hope that is in you, yet do it with gentleness and respect;