8 the Spirit, and the water, and the blood; and the three agree in one. 9 If we receive the witness of men, the witness of God is greater. For this is the witness of God [which] he has witnessed concerning his Son.

10 He that believes on the Son of God has the witness in himself; he that does not believe God has made him a liar, because he has not believed in the witness which God has witnessed concerning his Son. 11 And this is the witness, that God has given to us eternal life; and this life is in his Son.

Matthew Henry's Commentary on 1 John 5:8-11

Commentary on 1 John 5:6-8

(Read 1 John 5:6-8)

We are inwardly and outwardly defiled; inwardly, by the power and pollution of sin in our nature. For our cleansing there is in and by Christ Jesus, the washing of regeneration and the renewing of the Holy Ghost. Some think that the two sacraments are here meant: baptism with water, as the outward sign of regeneration, and purifying from the pollution of sin by the Holy Spirit; and the Lord's supper, as the outward sign of the shedding Christ's blood, and the receiving him by faith for pardon and justification. Both these ways of cleansing were represented in the old ceremonial sacrifices and cleansings. This water and blood include all that is necessary to our salvation. By the water, our souls are washed and purified for heaven and the habitation of saints in light. By the blood, we are justified, reconciled, and presented righteous to God. By the blood, the curse of the law being satisfied, the purifying Spirit is obtained for the internal cleansing of our natures. The water, as well as the blood, came out of the side of the sacrificed Redeemer. He loved the church, and gave himself for it, that he might sanctify and cleanse it with the washing of water by the word; that he might present it to himself a glorious church, Ephesians 5:25-27. This was done in and by the Spirit of God, according to the Saviour's declaration. He is the Spirit of God, and cannot lie. Three had borne witness to these doctrines concerning the person and the salvation of Christ. The Father, repeatedly, by a voice from heaven declared that Jesus was his beloved Son. The Word declared that He and the Father were One, and that whoever had seen him had seen the Father. And the Holy Ghost, who descended from heaven and rested on Christ at his baptism; who had borne witness to Him by all the prophets; and gave testimony to his resurrection and mediatorial office, by the gift of miraculous powers to the apostles. But whether this passage be cited or not, the doctrine of the Trinity in Unity stands equally firm and certain. To the doctrine taught by the apostles, respecting the person and salvation of Christ, there were three testimonies. 1. The Holy Spirit. We come into the world with a corrupt, carnal disposition, which is enmity to God. This being done away by the regeneration and new-creating of souls by the Holy Spirit, is a testimony to the Saviour. 2. The water: this sets forth the Saviour's purity and purifying power. The actual and active purity and holiness of his disciples are represented by baptism. 3. The blood which he shed: and this was our ransom, this testifies for Jesus Christ; it sealed up and finished the sacrifices of the Old Testament. The benefits procured by his blood, prove that he is the Saviour of the world. No wonder if he that rejects this evidence is judged a blasphemer of the Spirit of God. These three witnesses are for one and the same purpose; they agree in one and the same thing.

Commentary on 1 John 5:9-12

(Read 1 John 5:9-12)

Nothing can be more absurd than the conduct of those who doubt as to the truth of Christianity, while in the common affairs of life they do not hesitate to proceed on human testimony, and would deem any one out of his senses who declined to do so. The real Christian has seen his guilt and misery, and his need of such a Saviour. He has seen the suitableness of such a Saviour to all his spiritual wants and circumstances. He has found and felt the power of the word and doctrine of Christ, humbling, healing, quickening, and comforting his soul. He has a new disposition, and new delights, and is not the man that he formerly was. Yet he finds still a conflict with himself, with sin, with the flesh, the world, and wicked powers. But he finds such strength from faith in Christ, that he can overcome the world, and travel on towards a better. Such assurance has the gospel believer: he has a witness in himself, which puts the matter out of doubt with him, except in hours of darkness or conflict; but he cannot be argued out of his belief in the leading truths of the gospel. Here is what makes the unbeliever's sin so awful; the sin of unbelief. He gives God the lie; because he believes not the record that God gave of his Son. It is in vain for a man to plead that he believes the testimony of God in other things, while he rejects it in this. He that refuses to trust and honour Christ as the Son of God, who disdains to submit to his teaching as Prophet, to rely on his atonement and intercession as High Priest, or to obey him as King, is dead in sin, under condemnation; nor will any outward morality, learning, forms, notions, or confidences avail him.