"We know that no one who is born of God sin; but He who was born of God keeps him and the evil one does not touch him.  We know that we are of God, and the whole world lies in the power of the evil one.  And we know that the Son of God has come, and has given us understanding, in order that we might know Him that is true, and we are in Him who is true, in His Son Jesus Christ.  This is the true God and eternal life.  Little children, guard yourselves from idols."

John ends his letter by reminding us about how God shows Himself to us. 

And we know that the Son of God has come...
And given us understanding...
IN ORDER THAT WE MIGHT KNOW HIM...

All the gifts of God, all the presence of God, all the wisdom of God, so we might know Him.

This is what John's letter is all about...  so that we might know Him.

If you seek righteousness - seek Him.

He is Jesus the Christ.  Messiah.  Savior.