1 John 5:8

“And there are three that bear witness on earth, &c.] To the same truth of the sonship of Christ: the Spirit, and the water, and the blood; by the “Spirit” is not meant the human Spirit or soul of Christ; for however that may be a witness of the truth of his human nature, yet not of his divine sonship: and moreover cannot be said to be a witness in earth; rather the Gospel, called the Spirit, which is a testimony of Christ's person, office, and graces and is preached by men on earth; or else the gifts of the Spirit bestowed on men on earth, both in an extraordinary and ordinary way, by which they have been qualified to bear witness to this truth; or it may be the Holy Spirit itself is…”

“agree in one--"tend unto one result"; their agreeing testimony to Jesus' Sonship and Messiahship they give by the sacramental grace in the water of baptism, received by the penitent believer, by the atoning efficacy of His blood, and by the internal witness of His Spirit (Jo1 5:10): answering to the testimony given to Jesus' Sonship and Messiahship by His baptism, His crucifixion, and the Spirit's manifestations in Him (see on Jo1 5:6). It was by His coming by water (that is, His baptism in Jordan) that Jesus was solemnly inaugurated in office, and revealed Himself as Messiah; this must have been peculiarly important in John's estimation, who was first led to Christ by the testimony of the…”

“And there are three that bear witness in earth - This is a part of the text, which, if the reasoning above is correct, is to be omitted. The genuine passage reads, 1 John 5:7, “For there are three that bear record (or witness, μαρτυροῦντες marturountes) - the Spirit, and the water, and the blood.” There is no reference to the fact that it is done “in earth.” The phrase was introduced to correspond with what was said in the interpolated passage, that there are three that bear record “in heaven.” The Spirit - Evidently the Holy Spirit. The assertion here is, that that Spirit bears witness to the fact that Jesus is the Son of God, 1 John 5:5. The testimony of the Holy Spirit to this fact is…”

“And there are three that testify in heaven - The testimony of the Spirit, the water, and the blood, is by an eminent gradation corroborated by three, who give a still greater testimony. The Father - Who clearly testified of the Son, both at his baptism and at his transfiguration. The Word - Who testified of himself on many occasions, while he was on earth; and again, with still greater solemnity, after his ascension into heaven, Rev 1:5; Rev 19:13. And the Spirit - Whose testimony was added chiefly after his glorification, Jo1 2:27; Joh 15:26; Act 5:32; Rom 8:16. And these three are one - Even as those two, the Father and the Son, are one, Joh 10:30. Nothing can separate the Spirit from the…”

“there: Jo1 5:7 the spirit: Jo1 5:6; Mat 26:26-28, Mat 28:19; Joh 15:26; Rom 8:16; Heb 6:4 the water: Act 2:2-4; Co2 1:22 the blood: Heb 13:12; Pe1 3:21 and these: Mar 14:56; Act 15:15 1 John 5:9”