This is he that came by water and blood, even Jesus Christ; not with the water only, but with the water and with the blood. And it is the Spirit that beareth witness, because the Spirit is the truth. For there are three who bear witness, the Spirit, and the water, and the blood: and the three agree in one. If we receive the witness of men, the witness of God is greater: for the witness of God is this, that he hath borne witness concerning his Son. He that believeth on the Son of God hath the witness in him: he that believeth not God hath made him a liar; because he hath not believed in the witness that God hath borne concerning his Son. And the witness is this, that God gave unto us eternal life, and this life is in his Son (1 John 5:6-11).
The first letter of John has been a wonderfully encouraging treatise to the Christians of his day, confirming them in their faith while warning them about the dangers of false religion. As he begins to conclude his letter one can see John recapitulating his main themes and exhorting Christians to greater faithfulness in Christ Jesus. After his treatise on love (1 John 4:7-5:3), John has emphasized the importance of overcoming the world through obedient faith toward God (cf. 1 John 5:2-5).
Having established that believers can overcome the world through believing that Jesus is the Son of God (1 John 5:5), John turns to speak of the confirmation that Jesus is indeed the Christ, the Son of God. In so doing he returns to a prominent theme in the Gospel of John: the bearing of witness (cf. John 1:7, 8, 15, 32, 34, etc.). This witness is perceived in some “external” elements (Spirit, water, blood, v. 8) along with “internal” elements (eternal life, v. 11), providing sufficient confirmation to the believer that his faith is not in vain.
John begins by showing that Jesus came by both “water” and “blood” (1 John 5:6). This follows the established pattern of “two or three witnesses” as attested by Deuteronomy 19:15 as the standard for confirmation of evidence. The “water” refers to Jesus’ baptism by John whereby God the Father and God the Spirit both attest to Jesus’ divine Sonship (cf. Matthew 3:16-17, John 1:32-33), and the “blood” refers to His death on the cross for remission of sin, attested in part by John the Baptist in John 1:29 and the witness of the Spirit through Isaiah in Isaiah 53. In 1 John 5:7-8 John affirms that the Spirit also bears witness, and the Spirit is the truth (cf. 2 Peter 1:19-21). This leads to having the three witnesses in agreement: the Spirit, the water, and the blood. They testify to the truth of God in Jesus Christ.
This witness from God is far superior to any witness of man, and the witness of God is that He has testified concerning His Son (1 John 5:9). We can see this indirectly through the prophets (cf. Isaiah 9, 11, 53, etc.) and directly in the life of Jesus (Matthew 3:16-17, 17:1-5, John 12:28). John then makes a contrast between those who accept this witness and those who reject it: those who accept it have the witness in them, and those who reject it God has made liars (1 John 5:10). This witness would include God abiding with us in the Spirit (cf. 1 John 4:12-13), and our adherence to the faith once revealed for the saints (cf. Jude 1:3), but here is most particularly the eternal life that God provides to believers through the Son (1 John 5:11). We should not imagine that God somehow turns people into liars– instead, those rejecting God’s witness are made liars because God is true and what He has established must stand (cf. Romans 3:4).
It is important for us to make a textual note in regards to 1 John 5:7, which as rendered in the KJV features the Comma Johannem:
For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one (1 John 5:7 KJV).
This verse is not found in any of our Greek manuscripts save one copy that has a dubious past. It was inserted and established into the Latin translation of the Bible, the Vulgate, most likely as a strong affirmation of the trinitarian view of God. While many people are willing to make strenuous arguments affirming the textual validity of the Comma, the context makes it clear that it is an insertion: John is talking about those who witness in regards to Jesus as the Son, and the three that do so are the Spirit, the water, and the blood (cf. 1 John 5:8 KJV). The truth of God as One in Three Persons can be well established without recourse to this addition to Scripture.
John has powerfully established that we can be sure that Jesus is the Christ based upon His life and death and the testimony of the Father and the Spirit, and we enjoy the benefits of this witness through the eternal life that is given to us from the Father through the Son. Let us praise God for our salvation!