We believe that Jesus is the Christ, the Son of God. Why? What is the basis of our faith? John tells us: -- "This is he which came by water and blood, even Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth." Here is the witness of the water, the blood, and the Spirit.
1. We know that Jesus is the Christ, the Son of God BECAUSE HE CAME BY WATER. What does that mean? Water is an emblem for the written Word of God (John 15:3; Eph. 5:26; Tit. 3:5). We know that Jesus Christ, our Lord, is the Son of God, the anointed One, because he came according to and in fulfilment of all the types, promises, and prophecies of the Old Testament Scriptures (Lk. 24:27, 44-47).
2. We know that Jesus Christ is the Son of God BECAUSE HE CAME BY BLOOD. The sinlessness of his life, his obedience to God, and his miraculous powers are not sufficient to prove Christ's Deity. We see his Deity when we see the death which he accomplished as the sinner's Substitute upon the cross (Matt. 27:54). His death was a voluntary act (John 10:17-18), a vicarious atonement (John 11:49-52), and a victorious accomplishment (John 19:30).
3. And we know that Jesus is the Christ, the Son of God, BECAUSE THE SPIRIT BEARS WITNESS TO HIS DEITY. John the Baptist recognized Christ as the Messiah, the Son of God, by the descent of the Spirit upon him at his baptism, in the form of a dove. On the day of Pentecost the Holy Spirit bore witness to Christ's exaltation and enthronement as King, by his descent upon the assembled church. And the Spirit bears witness to Christ's Deity and dominion through the preaching of the gospel, convincing sinners, chosen and redeemed by him, that he has the power as the God-Man Mediator to give them repentance and the forgiveness of sins (Acts 5:30-32).
Every believer knows, with absolute assurance, that Jesus Christ is God the Son, the Son of God, our sovereign Lord, and our almighty Savior by the witness of the Word, the witness of the Blood, and the witness of the Holy Spirit.