'Testifying' in the Bible

and the Life [an aspect of His being] was manifested, and we have seen [it as eyewitnesses] and testify and declare to you [the Life], the eternal Life who was [already existing] with the Father and was [actually] made visible to us [His followers]—

This one is he who did come through water and blood -- Jesus the Christ, not in the water only, but in the water and the blood; and the Spirit it is that is testifying, because the Spirit is the truth,

because three are who are testifying in the heaven, the Father, the Word, and the Holy Spirit, and these -- the three -- are one;

and three are who are testifying in the earth, the Spirit, and the water, and the blood, and the three are into the one.