Who is Jesus? - Christ the Mediator.
From the Westminster Confession of Faith

I. It pleased God, in his eternal purpose, to choose and ordain the Lord Jesus, his only begotten Son, to be the Mediator between God and man: "Behold my servant, whom I uphold; mine elect, in whom my soul delighteth: I have put my Spirit upon him; he shall bring forth judgment to the Gentiles." (Isa. 42:1)
- "But with the precious blood of Christ, as of a lamb without blemish and without spot; Who verily was foreordained before the foundation of the world, but was manifest in these last times for you." (1 Pet. 1:19-20)
- "God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life." (John 3:16)
- "For there is one God, and one mediator between God and men, the man Christ Jesus." (1 Tim. 2:5)
... to be Prophet: "A prophet shall the Lord your God raise up unto you... him shall ye hear..." (Acts 3:22)
... to be Priest: "Christ glorified not himself to be made an high-priest; but he that said unto him, Thou art my Son, today have I begotten thee... Thou art a priest for ever, after the order of Melchisedec." (Heb. 5:5)
... to be King: "I have set my King upon my holy hill..." (Ps. 2:6) - "Of his kingdom there shall be no end." (Lk 1:33)
... the Head and Saviour of his Church: "Christ is the head of the church... he is the saviour of the body." (Eph 5:23)
... to be the Heir of all things: "... his Son, whom he hath appointed heir of all things..." (Heb. 1:2)
... and to be the Judge of the world: "He hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained..." (Acts 17:31)
God gave Him from all eternity a people to be his seed: "I have manifested thy name unto the men which thou gavest me out of the world: thine they were, and thou gavest them me; and they have kept thy word." (John 17:6) - "A seed shall serve him; it shall be accounted to the Lord for a generation." (Ps. 22:30) - "Yet it pleased the Lord to bruise him; he hath put him to grief: when thou shalt make his soul an offering for sin, he shall see his seed..." (Isa. 53:10)
... and to be by him in time redeemed, called, justified, sanctified, and glorified: "He gave himself a ransom for all, to be testified in due time." (1 Tim. 2:6)
- "Behold, I have given him for a witness to the people, a leader and commander ... nations that knew not thee shall run unto thee... for he hath glorified thee." (Isa. 55:4)
- "But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification and redemption." (1 Cor. 1:30)

II. The Son of God, the second person in the Trinity, being very and eternal God, of one substance, and equal with the Father, did, when the fulness of time was come, take upon him man's nature: "In the beginning was the Word, and the Word was with God, and the Word was God. And the Word was made flesh, and dwelt among us (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth." (John 1:1, 14)
- "... the Son of God is come... This is the true God, and eternal life." (1 John 5:20)
- "Who, being in the form of God, thought it not robbery to be equal with God." (Phil. 2:6)
- "God sent forth his Son, made of a woman, made under the law." (Gal. 4:4)
... with all the essential properties and common infirmities thereof, yet without sin: "As the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy... the devil... It behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people." (Heb. 2:14-17)
- "We have not an high priest which cannot be touched with the feeling of our infirmities; but was... tempted like as we are, yet without sin." (Heb. 4:15)
... being conceived by the power of the Holy Ghost, in the womb of the Virgin Mary, of her substance: "...the virgin's name was Mary. And behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS... The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee; therefore also that holy thing, which shall be born of thee, shall be called the Son of God." (Luke 1:27, 31, 35) - (Gal, 4:4).
... So that two whole, perfect, and distinct natures, the Godhead and the manhood, were inseparably joined together in one person, without conversion, composition, or confusion: "In him dwelleth all the fulness of the Godhead bodily." (Col. 2:9; Rom. 9:5)
- "Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit." (1 Pet. 3:18) - "God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory." (1 Tim. 3:16)
... Which person is very God and very man, yet one Christ, the only Mediator between God and man: "Jesus Christ our Lord, which was made of the seed of David according to the flesh, and declared to be the Son of God with power, according to the Spirit of holiness, by the resurrection from the dead." (Rom. 1:3-4)
- "For there is one God, and one mediator between God and men, the man Christ Jesus." (1 Tim. 2:5)

III. The Lord Jesus, in his human nature thus united to the divine, was sanctified and anointed with the Holy Spirit above measure: "Thou lovest righteousness, and hatest wickedness: therefore God, thy God, hath anointed thee with the oil of gladness above thy fellows." (Ps. 45:7) - "God giveth not the Spirit by measure unto him." (John 3:34)
... full of wisdom and knowledge: "In whom are hid all the treasures of wisdom and knowledge." (Col. 2:3)
... in whom all fulness dwells: "For it pleased the Father, that in him should all fulness dwell." (Col. 1:19)
... to the end, that being holy, harmless, undefiled, and full of grace and truth: "For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens." (Heb. 7:26) - "And the Word was made flesh, and dwelt among us... full of grace and truth." (John 1:14)
... he might be thoroughly furnished to execute the office of a Mediator and Surety: "How God anointed Jesus of Nazareth with the Holy Ghost, and with power; who went about doing good, and healing all that were oppressed of the devil: for God was with him." (Acts 10:38)
- "And to Jesus the mediator of the new covenant and to the blood of sprinkling..." (Heb. 12:24)
- "By so much was Jesus made a surety of a better testament." (Heb. 7:22)
... which office he took not unto himself, but was thereunto called by his Father: "No man taketh this honour unto himself, but he that is called of God... So also Christ glorified not himself to be made an high priest; but he that said unto him, Thou art my Son, to-day have I begotten thee." (Heb. 5:4)
... who put all power and judgment into his hand, and gave him commandment to execute the same: "For the Father judgeth no man, but hath committed all judgment unto the Son: and hath given him authority to execute judgment also, because he is the Son of man." (John 5:22, 27)
- And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth." (Matt. 28:18)
- "God hath made that same Jesus... both Lord and Christ." (Acts 2:36)
IV. This office the Lord Jesus did most willingly undertake: "I delight to do thy will, O my God; thy law is within my heart." (Ps. 40:7-8) - "Lo, I come to do thy will..." (Heb. 10:5-10)
- "No man taketh it from me, but I lay it down of myself..." (John 10:18)
- "He humbled himself, and became obedient unto death, even the death of the cross." (Phil.2:8)
... which that he may discharge, he was made under the law: "God sent forth his Son... made under the law." Gal. 4:4
... and did perfectly fulfil it: "Jesus answering, said... thus it becometh us to fulfil all righteousness. (Matt. 3:15) - Think not that I am come to destroy the law or the prophets: I am not come to destroy, but to fulfil." (Matt. 5:17)
... endured most grievous torments immediately in his soul: "He began to be sorrowful and very heavy... and being in an agony, he prayed more earnestly: and his sweat was as it were great drops of blood falling down..." (Matt. 26:37-44)
- About the ninth hour, Jesus cried with a loud voice... My God, my God, why hast thou forsaken me?" (Matt.27:46)
... and most painful sufferings in his body: Matthew, chapters 26 and 27.
... was crucified and died: "He became obedient unto death, even the death of the cross." (Phil 2:8)
... was buried, and remained under the power of death, yet saw no corruption: "Him... ye have taken, and... crucified.. whom God hath raised up, having loosed the pains of death: because it was not possible that he should be holden of it. Because thou wilt not leave my soul in hell, neither wilt thou suffer thine Holy One to see corruption." (Acts 2:23-27)
- "He, whom God raised again, saw no corruption." (Acts 13:37) - "Death hath no more dominion over him." (Rom. 6:9)
...On the third day he arose from the dead: "Christ died for our sins according to the scriptures; he was buried, and he rose again the third day according to the scriptures; and he was seen of Cephas, then of the twelve." (1 Cor.15:3-5)
... with the same body in which he suffered: "Then saith he (Jesus) to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust it into my side: and be not faithless, but believing." (John 20:25-27)
... with which he also ascended into heaven, and there sitteth at the right hand of His Father: "After the Lord had spoken unto them, he was received up into heaven, and sat on the right hand of God." (Mark 16:19)
... making intercession: "It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us." (Rom. 8:34) - "For Christ is not entered into the holy places made with hands... but into heaven itself, now to appear in the presence of God for us." (Heb. 9:24) - "He is able to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them." (Heb. 7:25)
... and shall return to judge men and angels at the end of the world: "For this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living... We shall all stand before the judgment seat of Christ." (Rom. 14:9-10; Acts 1:11)
- "It is he which was ordained of God to be the Judge of quick and dead." (Acts 10:42)
- "As the tares are gathered and burned in the fire; so shall it be in the end of this world..." (Matt. 13:40-42; 2 Pet.2:4; Jude 6)

V. The Lord Jesus, by his perfect obedience and sacrifice of himself, which he through the eternal Spirit once offered up unto God, hath fully satisfied the justice of his Father: "As by one man's disobedience many were made sinners; so by the obedience of one shall many be made righteous." (Rom. 5:19) - "How much more shall the blood of Christ, who... offered himself without spot to God, purge your conscience from dead works, to serve the living God?" (Heb. 9:14-16)
- "By one offering he hath perfected for ever them that are sanctified." (Heb. 10:14; Eph. 5:2; Rom. 3:25)
... and purchased not only reconciliation, but an everlasting inheritance in the kingdom of heaven, for all those whom the Father hath given unto him: "It pleased the Father that in him should all fulness dwell: And (having made peace through the blood of his cross), by him to reconcile all things unto himself... whether they be things in earth, or things in heaven." (Col. 1:19-20; Dan. 9:24-26) - "In whom we have obtained an inheritance..." (Eph. 1:11-14; John 17:2) "... having obtained eternal redemption for us... He is the mediator of the new testament..." (Heb. 9:12-15)

VI. Although the work of redemption was not actually wrought by Christ till after his incarnation, yet the virtue, efficacy, and benefits thereof, were communicated unto the elect in all ages successively from the beginning of the world in and by those promises, types, and sacrifices, wherein he was revealed and signified to be the Seed of the woman, which should bruise the serpent's head, and the Lamb slain from the beginning of the world, being yesterday and to-day the same, and for ever. (Gal. 4:4-5; Gen. 3:15; Rev 13:8; Heb. 13:8)

VII. Christ, in the work of mediation, acteth according to both natures; by each nature doing that which is proper to itself: (Heb. 9:14; 1 Pet. 3:18) yet, by reason of the unity of the person, that which is proper to one nature is sometimes in scripture attributed to the person denominated by the other nature. (Acts 20:28; John 3:13-16)

VIII. To all those for whom Christ hath purchased redemption, he doth certainly and effectually apply and communicate the same; (John 6:37, 39; John 10:15-16) making intercession for them; (1 John 2:1-2; Rom.8:34) and revealing unto them, in and by the word, the mysteries of salvation; (John 15:13-15; Eph. 1:7-9; John 17:6) effectually persuading them by his Spirit to believe and obey; and governing their hearts by his word and Spirit; (John 14:16; Heb. 12:2; 2 Cor. 4:13; Rom.8:9, 14; Rom. 15:18-19; John 17:17) overcoming all their enemies by his almighty power and wisdom, in such manner and ways as are most consonant to his wonderful and unsearchable dispensation.
(Ps.110:1; 1 Cor. 15:25-26; Mal. 4:2-3; Col. 2:15)