Late manuscripts of the Vulgate "testify in heaven: the Father, the Word and the Holy Spirit, and these three are one. " 8"And there are three that testify on earth: the" (not found in any Greek manuscript before the fourteenth century)
We accept human testimony, but God’s testimony is greater because it is the testimony of God, which he has given about his Son.
If you see any brother or sister commit a sin that does not lead to death, you should pray and God will give them life. I refer to those whose sin does not lead to death. There is a sin that leads to death. I am not saying that you should pray about that.
We know also 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 by being in his Son Jesus Christ. He is the true God and eternal life.