This is He who came by water and blood -- Jesus Christ; not only by water, but by water and blood. And it is the Spirit who bears witness, because the Spirit is truth.
He who believes in the Son of God has the witness in himself; he who does not believe God has made Him a liar, because he has not believed the testimony that God has given of His Son.
These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may [continue to] believe in the name of the Son of God.
If anyone sees his brother sinning a sin [which does] not [lead] to death, he will ask, and He will give him life for those who commit sin not [leading] to death. There is sin [leading] to death. I do not say that he should pray about that.
And we know that the Son of God has come and has given us an understanding, that we may know Him who is true; and we are in Him who is true, in His Son Jesus Christ. This is the true God and eternal life.