This is the one who came by water and blood, Jesus Christ, not with the water only but with the water and the blood. And the Spirit is the one that testifies, for the Spirit is the truth.
Those who believe in the Son of God have the testimony in their hearts. Those who do not believe in God have made him a liar by not believing in the testimony that God has given concerning his Son.
If you see your brother or sister committing what is not a mortal sin, you will ask, and God will give life to such a one-- to those whose sin is not mortal. There is sin that is mortal; I do not say that you should pray about that.
And we know that the Son of God has come and has given us understanding so that we may know him who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life.