Albert Barnes Commentary 1 John 5:8

"For there are three who bear witness, the Spirit, and the water, and the blood: and the three agree in one." — 1 John 5:8 (ASV)

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—marturountev,] the Spirit, and the water, and the blood." There is no reference to the fact that it is done "in earth." That 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 this 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 contained in the following things:

1. He did it at the baptism of Jesus (Matthew 3:16, Matthew 3:17).
2. Christ was eminently endowed with the influences of the Holy Spirit, as it was predicted that the Messiah would be, and as it was appropriate he should be (Isaiah 11:2; Isaiah 61:1; John 3:34).
3. The Holy Spirit bore witness to his Messiahship after his ascension by descending, according to his promise, on his apostles, and by accompanying the message they delivered with saving power to thousands in Jerusalem (Acts 2).
4. He still bears the same testimony in every revival of religion and in the conversion of every individual who becomes a Christian, convincing them that Jesus is the Son of God .
5. He does it in the hearts of all true Christians, for "no man can say that Jesus is Lord but by the Holy Ghost" (1 Corinthians 12:3; see also 1 Corinthians 2:3).

The Spirit of God has thus always borne witness to the fact that Jesus is the Christ, and he will continue to do it to the end of time, convincing yet countless millions that he was sent from God to redeem and save lost men.

And the water (1 John 5:6).

That is, the baptism of Jesus, and the scenes that occurred when he was baptized, furnished evidence that he was the Messiah. This was done in these ways:

1. It was proper that the Messiah should be baptized when he entered on his work, and perhaps it was expected; and the fact that he was baptized showed that he had in fact entered on his work as Redeemer (Matthew 3:15).
2. An undoubted attestation was then furnished to the fact that he was "the Son of God," by the descent of the Holy Spirit in the form of a dove, and by the voice that addressed him from heaven (Matthew 3:16–17).
3. His baptism with water was an emblem of the purity of his own character and of the nature of his religion.
4. Perhaps it may be implied here, also, that water used in baptism now bears witness to the same thing:
   1. as it is the ordinance appointed by the Savior;
   2. as it keeps up his religion in the world;
   3. as it is a public symbol of the purity of his religion;
   4. and as, in every case where it is administered, it is connected with the public expression of a belief that Jesus is the Son of God.

And the blood. There is undoubted allusion here to the blood shed on the cross; and the meaning is that this blood also bore witness to the fact that he was the Son of God. This it did in the following respects:

1. The shedding of the blood showed that he was truly dead—that his work was complete—that he died in reality, and not in appearance only (John 19:34, John 19:36).
2. The remarkable circumstances that attended the shedding of this blood—the darkened sun, the earthquake, the rending of the veil of the temple—showed in a manner that convinced even the Roman centurion that he was the Son of God (Matthew 27:54).
3. The fact that an atonement was thus made for sin was an important "witness" for the Savior, showing that he had done that which the Son of God only could do, by disclosing a way by which the sinner may be pardoned and the polluted soul be made pure.
4. Perhaps, also, there may be here an allusion to the Lord's Supper, as designed to set forth the shedding of this blood; and the apostle may mean to have it implied that the representation of the shedding of the blood in this ordinance is intended to keep up the conviction that Jesus is the Son of God. If so, then the general sense is that this blood—however set before the eyes and the hearts of men, on the cross or by the representation of its shedding in the Lord's Supper—is a witness in the world to the truth that Jesus is the Son of God and to the nature of his religion (1 Corinthians 11:26).

And these three agree in one (eiv to en eisi). They agree in one thing; they bear on one and the same point, namely, the fact that Jesus is the Son of God. All are appointed by God as witnesses of this fact, and all harmonize in the testimony that is borne.

The apostle does not say that there are no other witnesses to the same thing; nor does he even say that these are the most important or decisive that have been furnished. But he says that these are important witnesses and are entirely harmonious in their testimony.

(Regarding "water," see 1 Peter 3:21. Regarding "Blood," see Hebrews 13:12.)